Avoiding Iodine Deficiency

Avoiding Iodine Deficiency
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With a few caveats, the best source of iodine is sea vegetables.


Why does this 15-year-old look so unhappy? Maybe it’s because of the iodine deficiency in her diet that gave her this goiter. Everyone needs iodine, but this is especially important for people who want to eat well, since many healthy plant foods like flax, soy, and broccoli have what are called goitrogenic compounds, which can interfere with thyroid function in people with marginal iodine intake. So does that mean we shouldn’t eat broccoli? Of course not. We just need to get enough iodine in our diets. It’s actually really simple to do. Rather than using natural sea salt, use iodized salt, and you’ll probably get all the iodine you need.

But if, for good reason, we don’t add salt to our food, we just need to get our iodine somewhere. Cow milk drinkers get it because iodine-containing disinfectants are used to disinfect the milk tanks, and so the iodine sort of leaches into the milk. The best source is sea vegetables, or you can get it in a multivitamin.

But I do encourage people to develop a taste for seaweed. It’s a wonderful food—dark green leafies of the sea. It may even prevent cancer. Seaweed inhibits human cancer cell growth, and this new study suggests it may even have a therapeutic potential for people battling liver cancer. Sea vegetables have lots of B vitamins and minerals—particularly the trace minerals, like iodine.

The problem with seaweed is that we can actually get too much iodine. The recommended daily intake is 160 micrograms a day, but the World Health Organization places the safe upper limit at 1,000 micrograms a day. So that’s not a huge amount of wiggle room. And it’s less for kids—300 micrograms or so may be too much for a five-year-old. This much laver or nori—a two-ounce bag—has enough iodine to last an adult a week. This much dulse; a month. This much wakame; two months. And one little bag of kelp; five years. A quarter gram a day of kelp is too much. And it would be hard to spread that little amount of kelp over five years, so I recommend going with one of these other sources.

Do not, however, eat hiziki. The reason sea vegetables are so wonderful is that they are packed with trace minerals; they just soak them up right out of the seawater. Hiziki, though, may also absorb bad minerals like arsenic. One seaweed species in particular, hiziki, sucks up so much arsenic that governments around the world are now warning consumers not to eat it. From the US EPA, to the British government, to New Zealand, to Canada—even the Chinese government. Here’s what it looks like. Note the two different spellings. No longer should anyone eat this—at least not on a regular basis. Lots of other wonderful types of seaweed out there without this problem, so we can get the anti-cancer benefits without the arsenic.

To see any graphs, charts, graphics, images, and quotes to which Dr. Greger may be referring, watch the above video. This is just an approximation of the audio contributed by veganmontreal.

Please consider volunteering to help out on the site.

Why does this 15-year-old look so unhappy? Maybe it’s because of the iodine deficiency in her diet that gave her this goiter. Everyone needs iodine, but this is especially important for people who want to eat well, since many healthy plant foods like flax, soy, and broccoli have what are called goitrogenic compounds, which can interfere with thyroid function in people with marginal iodine intake. So does that mean we shouldn’t eat broccoli? Of course not. We just need to get enough iodine in our diets. It’s actually really simple to do. Rather than using natural sea salt, use iodized salt, and you’ll probably get all the iodine you need.

But if, for good reason, we don’t add salt to our food, we just need to get our iodine somewhere. Cow milk drinkers get it because iodine-containing disinfectants are used to disinfect the milk tanks, and so the iodine sort of leaches into the milk. The best source is sea vegetables, or you can get it in a multivitamin.

But I do encourage people to develop a taste for seaweed. It’s a wonderful food—dark green leafies of the sea. It may even prevent cancer. Seaweed inhibits human cancer cell growth, and this new study suggests it may even have a therapeutic potential for people battling liver cancer. Sea vegetables have lots of B vitamins and minerals—particularly the trace minerals, like iodine.

The problem with seaweed is that we can actually get too much iodine. The recommended daily intake is 160 micrograms a day, but the World Health Organization places the safe upper limit at 1,000 micrograms a day. So that’s not a huge amount of wiggle room. And it’s less for kids—300 micrograms or so may be too much for a five-year-old. This much laver or nori—a two-ounce bag—has enough iodine to last an adult a week. This much dulse; a month. This much wakame; two months. And one little bag of kelp; five years. A quarter gram a day of kelp is too much. And it would be hard to spread that little amount of kelp over five years, so I recommend going with one of these other sources.

Do not, however, eat hiziki. The reason sea vegetables are so wonderful is that they are packed with trace minerals; they just soak them up right out of the seawater. Hiziki, though, may also absorb bad minerals like arsenic. One seaweed species in particular, hiziki, sucks up so much arsenic that governments around the world are now warning consumers not to eat it. From the US EPA, to the British government, to New Zealand, to Canada—even the Chinese government. Here’s what it looks like. Note the two different spellings. No longer should anyone eat this—at least not on a regular basis. Lots of other wonderful types of seaweed out there without this problem, so we can get the anti-cancer benefits without the arsenic.

To see any graphs, charts, graphics, images, and quotes to which Dr. Greger may be referring, watch the above video. This is just an approximation of the audio contributed by veganmontreal.

Please consider volunteering to help out on the site.

Doctor's Note

Other videos on iodine include:

For more on the health benefits of seaweed, see Which Seaweed is Most Protective Against Breast Cancer?

For further context, check out my associated blog posts: Do Eden Beans Have Too Much Iodine? and Nutmeg Toxicity.

If you haven’t yet, you can subscribe to my videos for free by clicking here.

241 responses to “Avoiding Iodine Deficiency

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  1. I have watched all five volumes of your DVDs, but it is a lot of information and I don’t have it all memorized. I know that you have a video somewhere about kombu, but I couldn’t find it on this site. So, I’m hoping it is OK to ask the question here under this video which is related:

    I thought I remember you saying that we should stay away from kombu because it has too much iodine? I like to put a sheet of kombu (maybe a 2 by 4 inch sheet) into pots of grains and beans that I cook. Mostly I throw away the kombu that is left at the end and eat the grains over the course of a week. So, would I be getting too much iodine if I do that?

    Also, sometimes I actually like to just snack on nori. But the nori goes down pretty fast. I give some to my dog, but most of it ends up in me. How many sheets would be too much in a sitting? In a week?

    (And fyi: a search on your site for Kombu turned up nothing – except for the kombuchi tea. Also, a search on nori turned up nothing. I do hope that lots of key words will be added to the videos.)

    Thanks for any guidance you can provide on kombu and nori. I want to get the iodine from food if I can, but I’m struggling to figure out how to get just the right amount (not too much or too little) easily.

    1. What an opportune time for this question–I’m actually going to posting about Kombu on Friday–stay tuned. I’m so glad you got so much out of my DVDs (all proceeds to charity).

      1. re: “I’m so glad you got so much out of my DVDs…” YES! I highly recommend the DVDs to people. This website is wonderful because people can see individual videos on-demand and because of the interactive nature of this site.

        However, seeing a video-here, a video-there does not give one the big picture. By seeing all the videos together and in order, one starts to see a pattern that is compelling. To people reading this: Go get those DVDs and show them to your whole family! And then to anyone else you care about.

      2. What about cranberries as a good source of iodine? By the way, I think you’re great but Facebook groups using your name are really terrible. You might want to take a look. I got booted from all three. One for asking a meat eater why he joined the group (go figure), one for saying cranberries are a good source of iodine, and the other I guess because the second one removed me. All my comments were removed as well. It’s ridiculous. I know you say you do the research so we don’t have to but I still like to do research when totally changing a lifestyle and the lifestyle of those I love and care for. Surely, you would agree with that.

    2. Hello, I would also like to know the answer to this question. My wife is Japanese and frequently uses Konbu to make a nice broth for the soup. I have sometimes eaten this up, which I will now stop doing (I am probably good on my iodine for like 10 years now), but is the amount of iodine in the broth at a dangerous level?

  2. FYI: I have submitted an email question to Maine SeaCoast Vegetables re: some apparently incorrect information on the nutrition facts label on their Laver. The bag pictured in this video is labeled as containing 1 oz, not 2 oz, yet the label on the back of the bag says it contains 8 7gm servings. I’ll update when I hear back from them. Nevertheless, I am planning on purchasing some Laver to get my iodine from a nutritious whole food instead of from a supplement.

    1. @Karen Lavine are you still using Main Coast Sea Vegetables / Seasonings products and did they get back to you with details on how much iodine per serving? I’ve started using their Seasonings products [ https://www.amazon.com/dp/B00BQ4MWNW/ and https://www.amazon.com/dp/B00CQ7K5QO/ ] on salads and have concerns given both are > 100% iodine RDA per tsp and the packaging warns of heavy metals, e.g. arsenic, even though Dr. Greger’s videos on iodine and sea vegetable sources says only Hiziki / Hijiki should be avoided for that reason.

  3. I am just wondering, considering the massive contamination of fish in the sea all over the world [even the Antarctic as you said!], surely seaweed is also contaminated too? It is …from the same sea after all. Any evidence-based thoughts?!!!

    1. wickedchicken: I don’t know the answer to your question as a fact, but I have some ideas that you might consider:

      1) Dr. Greger has one or more videos on this site that talk about contaminates getting concentrated the further one moves up the food chain. So, even if there are some contaminates in sea plants/seaweeds, there would be a lot more in sea animals. You should generally be able to greatly minimize exposure by sticking to the plants. In other words, it would not be appropriate to equate the two just because there might be some contaminates in seaweed.

      2) While there is sea contamination all over the world, it is probably not true that there is equal contamination in every part of the sea all over the world. Think about our air: Yes, the planet shares air. However, some cities have a lot more polluted air than others. Also, we know from Dr. Greger’s videos that some sea plants just seem to suck up the contaminants while others are not as bad.

  4. Hi Dr Gregger,
    I use half a teaspoon of agar-agar powder in 946 ml of soymilk to make my yogurt. Unfortunatly, I was unable to find the iodine content of agar-agar. Should I stop using agar-agar until until the iodine content is known ?

  5. Hi Chrifou, Agar-agar is a mixture of two polymers derived from red algae and should not contain iodine. So I would continue using the product.

  6. Dear Dr. Greger:
    I live in Chile, and here I haven’t seen any of those seaweeds… ¿What about Nori and cochayuyo (durvillaea antarctica)?
    Thank you!

  7. wow, thanks – this is new information to me. i probably am way overdosed on kombu kelp and hijiki – are we concerned even about organic and sustainably harvested hijiki that i get from small scale operations like natural food coop? too bad, it’s a nice sea veg in miso soups

  8. How does this guidance apply to someone who has Hashimoto’s Thyroiditis and is taking Levothyroxine on a daily basis? Same guidelines?  I’d really hate to limit my intake of flax, broccoli, cabbages, etc.

    1.  Since you are taking a thyroid supplement you don’t need to worry since the supplemental hormone already contains the iodine. So you should be able to consume the flax, broccoli, cabbage etc. There are other chemicals in the environment that can affect your glands see… http://nutritionfacts.org/video/the-problem-with-organic-salmon/. Of course you will need to get your thyroid level checked periodically and work with your physician to make sure you are taking enough and not too much. 

      1. Dr. Forrester, I also have Hashimoto’s and take a thyroid supplement (Thyrolar, which contains both T3 and T4 since my body does not do the conversion well). If I start eating seaweed, is this likely to have an impact on the Thyrolar dosage requirements? This is especially important for me because the standard thyroid tests do not seem to measure my thyroid levels accurately … (I’m told by my endocrinologist that this is true for about 1/3 of thyroid patients) … so I want to anticipate any possible problems rather than try to diagnose them later. Thank you.

  9. As for the arsenic, would that not depend on the source and lo0cation? Is arsenic in all ocean water all over the world and why would this one sea veggie suck up arsenic and the others do not?

  10. Here’s something to ponder on. Most people today get iodine from iodized salt, milk and fish. Vegans can get it from seaweed. I got thinking about when we were evolving. We didn’t always live by the sea so where did we get our iodine? Where do other primates get their iodine? Are their needs less perhaps?

    1.  Iodine is naturally occurring in plant foods in small amounts due to extraction from the soil. Current iodine levels in the soil due to current farm practices are near zero.

  11. With regards to being too iodine laden, I buy an inexpensive shaker of kelp at the health-food store of Main Coast brand’s Sea Seasonings. They tell you on the label that just 1/4 teaspoon (note: not tablespoon) is 20 times the RDA serving. So I take measure out a few little shakes on a spoon that looks about 1/20 of a 1/4 tsp and then I don’t have to worry about it.

    This isn’t much of a bother, but the reason I choose this over other methods is that while I like sheets of seaweed, they give me reflux and/or diarrhea. And I don’t like the more measured supplements because of all the added “stuff”. After just a few times of doing this I’m pretty used to what a few sprinkles should look like, so I think I am getting the right amount each time.

    Still, having said all that, I would love it if I could get a little measuring spoon, like some of those horrid little sweeteners have, that gives you a tiny but precise amount. If anyone has a recommendation for where to buy a scoop that is .0125 of a teaspoon (1/20 x 1/4), I’d love to hear the suggestion.

    1. Did you ever find a tiny scoop? I recently bought some kelp powder to try out. Previously I have used Lugol’s solution for iodine. Instead of sprinkling a small amount on food I’m considering mixing 1/4 tsp of kelp powder with 1L of water then spread that water out over time drinking 50ml each day.

    2. I contacted Maine Coast sea vegetables and they say that “Kelp Blend Granules has approximately 1450 mcg in 1 teaspoon. ¼ of a teaspoon may have as much as 362 mcg!”

      So half a 1/4 teaspoon is 181 mcg which is the RDA.

      The amount of Iodine for a healthy adult should be 150 mcg so you’re right there with 1/8 of Kelp.

      Where did you get your information? This info is directly from Maine Coast! Thanks just curious!

    3. You can buy stainless steel mini scoops from Amazon. Mine are fun as they say things like a tad, a smidgen, etc. They just make me chuckle…..

  12. I am thoroughly confused about eating goitrogens. A few
    years ago, my TSH tested at the upper ranges of normal. I chose to lower it to
    an optimal (less than 2.0) level by taking Armour thyroid. I have found that
    the foods that make up most of my diet—cruciferous veggies, soy nuts,
    strawberries, almonds, peanut butter, sweet potatoes, and spinach—are the foods I am supposed to avoid. I understand that it is beneficial to eat them cooked, but should I avoid them? That is a lot of nutritious food to exclude. If I
    avoided these foods, would my TSH be lower on its own (without Armour?) Should I continue to eat those foods, but take Iodoral? Help!

    1. You need to maintain an adequate iodine intake and iodoral is a good choice if you are not consuming any iodized salt. See Dr. Greger’s video on goitrogens… http://nutritionfacts.org/video/overdosing-on-greens/. Even moderate intake of raw goitrogens are okay if in moderation… you can overdo just about anything including iodine… see http://nutritionfacts.org/video/too-much-iodine-can-be-as-bad-as-too-little/. As far as the diagnosis of low thyroid it is sometimes a challenge. Medical recommendations seem to always be lowering the treatment thresholds. It would be helpful to have baseline levels for individuals to check for the need for medication. The reality is the blood markers need to be evaluated in conjunction with symptoms so it is important to work with a knowledgeable physician.

      1. This is a great response Dr Forrester. I have been whole foods plant based, (home-made food with no oil, no added salt at home) for 3 years but have normal labs for T3 and T4 but clearly have hypothyroid symptoms and nodules monitored by regular ultrasounds. So I am going to start on iodine (Iodoral) to see if this helps since I get no sources of iodine on a regular basis. We shall see how it goes.

      2. Just one comment about the Iodoral. One tablet contains 5 mg of iodine and 7.5 mg of iodide. This is more than the recommended RDA but equal to what might be found in Japanese diets. Is this amount safe?

  13. Dr. Greger does not recommend Kelp as a good source of Iodine, however, what about the supplements at the store that are Kelp based. I think I looked at the nutritional info on the bottle and it was 600 mcg per dose which is about in the middle of Dr. Greger’s and the WHO recommendations. Another issue I’m confused about is that some of the companies are recommending that IODIDE be present in the supplement for better assimilation…is this a factor to consider while trying to choose a good supplement?

  14. Get the Maine Coast dusle granules instead, they have about 300-350 mcg of iodine per teaspoon so you can measure a lot more easily.
    I’ead that the Japanese have around 5-10 mg of iodine a day, which is well over the upper limit of 1 mg. They don’t seem to have any problems. Shouldn’t this mean that the upper limit should be increased? Why is that amount of iodine ok for them but not for anyone else?

  15. My mother (61 y.o) had a Subtotal Thyroidectomy in 1992 due
    to Papillary Carcinoma and had a radioactive therapy (I131). Since then and to this day she takes Eltroxine and the TSH is about 0.05. In 2010 she was diagnosed with recurrent tumor
    size 12 mm that wasn’t change in follow up U.S.
    I wonder if she can eat the broccoli family and other goitrogenic food? In
    addition, can she eat food that contain Iodine?

    1. I saw Dr Greger this morning at a conference in Montreal and told him about my thyroid cancer (i had a total thyroidectomy last december) and asked him if i should avoid cruciferous vegetables or soy. His answer was that there is no problem as lon as i make sure to eat enough iodine.

      I wanted to ask him after the conference how much iodine someone with no thyroid should eat. Is it the same amount as someone with their thyroid, but i didn’t have the chance to ask him.

      Dr Greger, if you read this could you please give more information about this?

  16. Hi, I have hypothyroidism but am not taking any meds. My bloods are always within normal range, but I strugglt to lose weight, have very dry skin, eyebrows have gone on outer edges, have carpal tunnel and fatigue etc etc. I have recently changed to a vegan diet and eat plenty of kale, saur kraut, broccoli, cauliflower and nuts, among other foods. Advice please on what is good for natural treatment of hypothyroidism.

  17. What about trans-dermal application of iodine? Does “painting” Lugol’s on your skin help with eliminating a deficit, not necessarily maintaining a balance? Does evaporation time of iodine on skin indicate deficiency, or lack of? Is selenium required to help with iodine absorption, as found in one Brazilian nut?

  18. Hey there,

    I was just wondering if for this recommended daily amount we must eat it daily or if we can just eat the daily amount all added up once per week etc. I guess this question extends to daily amounts in general.

  19. A concerned Vegan…

    Dr. Greger,

    I love your site and watch your YouTube videos constantly –

    Thank you for the work that you do and the information that you provide to we who do not trust in the medical industry’s current philosophy – “Don’t Cure Disease, Treat It. No money in curing disease”.

    Now, my query –

    I am absolutely Vegan – even to a point of no sugar, no white flour or white potatoes, only use a trace of oils – and have been for 6 months…

    However, I just had a lipid panel completed and my Cholesterol is a whopping total of 222 (LDL 125, HDL 85, and triglycerids 61). I do have an elevated Thyroid level at 3.2 (desired range 0.3-3.0).

    I briskly walk 6+ miles a day and spend an hour in the gym.

    Is there any reason to be concerned over these numbers?
    Does an elevated Thyroid have an affect on Cholesterol levels?
    Is there anything else I should be doing to reduce my cholesterol?

    Thanks again for what you do.


      1. Thank you so much for responding… I love watching your videos. They are funny yet so so informative. I do have to say i have been on meds for my thyroid it was levoxyl 50 mcg. When it was recalled a fews month back I started taking synthroid 50 mcg it was so strong I cut the dose in half to 25 mcg a day…. I have now started back on the 50 mcg and I am going to start taking CholestOff 2 grams a day and hopefully this will be enough to drop the LDL and Total Cholesterol. Thanks again for caring Mary

  20. Why isn’t there more clinical studies on iodine supplements such as lugors? There’s a whole subculture of folks taking large doses of iodine, both on their own and with Dr.s supervision to cleanse themselves of bromine, flourine, chlorine. Is this really an issue? Sure wish there was a more definitive study of iodine’s efficacy as a supplement.

    1. Do a web search on Dr. Brownstein. He is one of the iodine experts. He’s been treating people for years with iodine.


      I take 25-50mg of lugols every day. My cholesterol dropped 40 points without changing my diet(I have a plant based diet). I feel more alert taking iodine. Iodine is like a plant based diet, the medical community doesn’t make any money off it.

      There’s no money in healthy and dead people. Sick people make the medical community wealthy. There’s no financial incentive for doctors to get people well.

      If you watch Greger’s videos than you are probably more informed about the health benefits of nutrition than most docs.

      BTW, seaweed has bromide in it. Take lugols.

    2. I had low hypothyroid for years and took lugol’s without having enough blood tests. I now have thyroid nodules and am hyperthyroid, ending up in hospital twice with arterial fibrillation. It is so much more dangerous being over than under!! I now take a homeopathic Thycalm twice a day to keep it under control. Dont make the same mistake I did!

      1. Linda: could you please tell us how much Lugol’s you were taking? I’m considering taking it, but it seems from their website that even just 1 drop per day is 2,500 mcg per day, which is over 10x the RDA. Your story could help people avoid a similar fate (re hyperthyroid).


        1. I was taking a drop every couple of days, after reading an article by Dr Brownstein. My mistake was not going back for a blood test after a month or so, I just kept taking it.Kelp tablets would have been slower, but safer.
          I now have an extra lobe on my thyroid, which I may have removed. I am controlling my sysmptoms [weight loss, rapid heart beat] with Thycalm, a homeopathic spray.
          I hope this is a cautionary tale to you all.

            1. Probably a couple of years. I as living on our boat and sailing around the Whitsundays so didn¹t visit any doctors for my usual blood tests because I felt good. Then I noticed I was eating a lot, but still loosing weight [no problem with that!!] But then when I got into bed at night my heart was thumbing and beating to fast for about 1./2 an hour, so I ha some blood tests which showed I was hyper

  21. (1)Wakame has no English name. Alaria is a brown seaweed in genus Alaria but wakame is a brown seaweed in genus Undaria. They have both been placed in family Alariaceae, order Laminariales, class Phaeophyceae, division Heterokontophyta, kingdom Chromalveolata. Technically, brown seaweeds such as kombu (kelp), arame (kelp), limu moui (kelp), mozuku, hijiki, and wakame are NOT plants (in kingdom Plantae). However, red seaweeds such as nori (laver), ogo (limu), and dulse are plants (placed inside of kingdom Plantae):

    (2)According to the following study, “When kombu is boiled in water for 15 minutes, it can lose up to 99% of its iodine content….”

    (3)According to the Linus Pauling Institute, a very high intake of iodine will slightly increase our risk of developing thyroid papillary cancers but slightly decrease our risk of developing thyroid follicular cancers. Thyroid papillary cancers are less aggressive and have a better prognosis than thyroid follicular cancers:

    (4)The Japanese in Japan who eat high-iodine brown seaweeds raw (uncooked) tend to have lower total cancer rates compared to Japanese in Japan who eat high-iodine brown seaweeds boiled (much lower in iodine):
    Apparently, this lower cancer rate among raw seaweed eaters can be explained by: (a)the good saltwater bacteria from the ocean, which provide an enzyme which allows humans to digest the polysaccharides in seaweeds, (b)the phyconutrients in brown seaweeds, (c)the phytonutrients in red seaweeds, and (d)the iodine, which like zinc and selenium, is a beneficial antioxidant.

  22. I’ve seen seaweed sold at Costco but it didn’t list the type of seaweed. Ingredients just list ‘seaweed’. Should this be avoided since it might be kelp? Also, last year my cat died as a result of hyperthyroidism. Since you put out this video, I noticed that a lot of cat and dog food contain dried kelp as an ingredient. I would think that someone in the veterinary world would have made a connection and found another source for iodine.

  23. I just got 100g of kelp powder from the health food store! Considering sprinkling it over my garden now! I also put a 1/4tsp of it in my breakfast porridge. It tasted a bit nasty, but forced it down because i thought it was good for me…wrong!

  24. Dr. Greger, this was very informative and I enjoy your data-driven videos. Do you have any information on the seaweed Bladderwrack as to the iodine content?

    1. I did a simple search of ‘cranberry iodine’, and found 4 ounces of raw cranberries to contain about 400 mcg of some sort of iodine. There was no mention of whether these were coastal grown berries or what. And who eats raw cranberries?

    2. My endocrinologist told me the same thing and I just found this: http://bembu.com/iodine-rich-foods
      (The same site also mentions that potato skins are an excellent source of iodine.)


      Cranberries have a rich color and a unique flavor. If you’re able to
      enjoy the sour taste, cranberries provide many health benefits. They
      have a high concentration of Vitamin C, Vitamin K, and fiber, and
      they’re known to prevent urinary tract infections. They’re also a
      stellar source of iodine; four ounces of these tart treats contains well
      over the recommended daily value of iodine.

      Serving Size (4 ounces), 400 micrograms of iodine (267% DV), 52 calories.

      1. Hi,

        I also found this website claiming that 4 oz of cranberries contains 400 micro grams of iodine, but I cannot verify the information.
        The USDA database does not include the iodine content of cranberries – see https://ndb.nal.usda.gov/ndb/foods/show/2191?n1=%7BQv%3D1%7D&fgcd=&man=&lfacet=&count=&max=&sort=&qlookup=&offset=&format=Full&new=&measureby=&Qv=1&ds=&qt=&qp=&qa=&qn=&q=&ing=

        This 1928 study found a much lower 26-35 parts per billion (micro grams) in a 500 gm. if my math is correct this is closer to 7 micro grams for 4 oz.

        It would be great if Nutrition Facts could help provide a reliable source verifying the correct level of iodine in cranberries.

        Thank you for the great information.

      2. For me, Cranberries aren’t enjoyable to eat raw. Instead I’ll put 4 oz. of cranberries into my morning fruit/veggie smoothie. You can barely taste them!

  25. I am a vegan with vegan children. If i were to use himalayan salt in my cooking would that be enough to avoid an iodine deficiency?

    1. Luz: How wonderful to hear of another vegan family! Your children are so lucky to have a mom like you who gets it. I sure wish I had been vegan growing up.

      I’m not an expert on the matter of salt, but I have done my own research in the past. I don’t know how valid it is, but I was left with the impression that you can not rely on “natural” salts for sufficient iodine intake. There is either not enough and/or the amount is not consistent. If it were me, I would want to make sure my family got a reliable source of the right amount of iodine.

      Good luck.

  26. “Until nearly five years ago, Americans who got dairy, bread, and meat in their diets got plenty of iodine, he explains. Machines used in production were cleaned with an iodine disinfecting solution, so some iodine ended up in dairy, bread, meat products. That ended when companies quit using iodine disinfectant.

    Iodized salt is rarely found in canned, frozen, or boxed food, says Maberly. French fries and other snack foods mostly contain regular salt — not iodized salt.”


  27. Would about kelp if the concentration is controlled? I found some kelp: Iodine
    270 mcg

    (Laminaria digitata & ascophyllum nodosum)

    It has 2 scoops and lots of servings for cheap. Is that ok?

  28. Hypothyroid Questions

    I gave been a vegetarian for 17 years and a vegan for just 10 months. I was hyperthyroid in my teens and twenties and took oral medication, the name of which I don’t remember. My thyroid levels were normal in my 30s and 40s with no medication. I became hypothyroid in my 50s and now 60s. My doctor has tried me on synthroid, levothyroxin, and now, with the most success, armor thyroid. It really bothers me that this is from pigs. So, finally to my questions.

    Can hypothyroid disease be reversed to a point where no medication is needed?
    Am I getting all of the awful effects of eating pork by taking this pill?
    I have low blood pressure and now salt (iodized) my food (I don’t eat processed food) more now than I used to, which is still not very much. Is this a good idea?
    I tried nori, but noticed that the little packet of desiccant in the packages are lye. Yikes!

    I’m know that you can’t give specific medical advice to me, but I have watched you videos on thyroid, pork, animal protein, etc. and would be interested to hear any research related to my questions.

    Love your videos!!!
    Westlake, Ohio

  29. I need iodine and don’t use enough salt to make it worthwhile. Like many folks who grew up on the ocean and learned to body-surf badly at a young age – I refuse to eat sea weed. I have tried to like it – I really have. It always tastes like drowning to me. Most of the sea weed I have eaten in my life has been involuntary while have my face ground into the sand and trying to figure out which direction the air is when a wave is crashing on me. So….no, No NO on sea weed. Could I please have some useful information on supplements, requirements, liquid or tablet – that sort of thing. I am already hypothyroid likely from iodine deficiency but sea weed is just not going to happen. I will go back to fish first. Please help.

  30. In Japan the serving/portion of Wakame, is only about 5 grams per person (per soup bowl) in Miso soup, or in other Japanese dishes using Wakame, the normal serving size per person is only about a handful, enough to fill a small serving dish/bowl. A little bit of a wide variety of food is served daily, and eaten often. Wakame is also good for keeping you regular.
    As to Konbu, only a 15 x 15 cm sheet is used to make broth, it is soaked for 30mins then simmered, removed before boiling point, and the actual konbu sheet is not consumed. Unfortunately nowadays a lot of packaged “instant” broth powder is used (with additives etc) instead of making the broth from scratch.
    I hope this helps people who are wondering about the portions.

  31. Ok i need some good help here, im thoroughly confused. I’m 26 5’6″ 114 lbs, In generally well health, I’m currently on a Vegan Diet. I was taking 1g of Seaweed for Iodine supplement since i DO NOT use Iodized salt. Back when i was eating iodized salt My T4 was 1.000 ng/dl. My TSH Level was 2.22 ng/dl.

    I recently stopped supplementation as advised by my Dr. since the idea was i eat enough prepackaged foods to provide enough iodine.(and from the research i found prepackaged foods in the USA are largely using Non-Iodized salt. please see sources below.) So after 4 weeks of No Iodine supplementation either from sea weed or from added iodized salt. Now my T4 is 1.11 ng/dl. and my TSH is 3.99 ng/dl.

    So what is going on? Should I take Iodine supplementation or not, and if not where am i getting my iodine? Im so confused and this causes me lots of worry anyone that knows what they are talking about let me know what you think. btw the standard ranges are below as well as sources to support my statements.

    Standard Ranges:
    TSH 0.34-4.82 uIU/mL

    FREE, T4 0.76-1.46 ng/dl

    “Processed foods, however, such as canned soups, almost never contain iodized salt.” [1]

    “Although iodized salt is a principal source of dietary iodine, suggesting that reduced salt intake could lead to iodine deficiency, the salt in most processed foods in the United States is not iodized “[2]

    “Most of the sodium in the American diet comes from prepared or processed food, and most food companies don’t use iodized salt. “[3]

    “3.2 North America.

    In the USA, iodization is permitted on a voluntary basis at a level of 77ppm as KI, however,

    virtually none of the salt sold to food processors is iodized. “[4]






  32. I use “sea seasoning” kelp granulates. 1 tsp = 900% RDV, so I just sprinkle 1/8 tsp in my shake. :-)

    It’s tough to get sea veggies around here…

    1. Faizah: From what I have read, the “natural” salts contain only trace amounts of minerals, and you can’t count on any specific amount of mineral being in any particular batch. So, I wouldn’t count on the Himalayan pink salt for being anything other than salt.

      That’s just what I read. I don’t know it for a fact. But for something so important, I would want to be sure before I relied on a particular food for a vital nutrient.

  33. Dr. Gregor or NF Team,

    Could you possibly make a quick edit to this video so that the amounts of seaweed in the packages are shown? Saying “this much” contains a month’s worth (etc) of iodine is more helpful if we actually know what that “this much” is.

    Thank you for all the great information and videos.

    1. An edit is actually much needed since Dulse and Wakame from that brand actually have very similar iodine concentrations are both equivalent to two months
      @disqus_EXJURIXKLQ:disqus @Toxins:disqus could you correct the “one month supply” to “two months” ?
      Dulse 780% DV per serving (7g) * 8 servings per 2oz (56g) pack
      Wakame 770% DV per serving (7g) * 8 servings per 2oz (56g) pack
      See iherb links and pictures :

      1. Youcef: Neither Toxins nor I have the power to change the videos or scripts. But I believe Dr. Greger tries to read every comment. And when he is able, I believe he tries to post corrections when warranted.

        Thanks for your post/links. I still find this topic very interesting and often on my mind. I appreciate any info I can get.

    1. Would also like to know this as I noticed improvements when I made myself some fresh cranberry juice but A: I’m not keen on it: B: it’s an expensive source, C: I can’t find and wouldn’t want to pay out for organic cranberries really!

  34. what about spiraling? Is that a good source of iodine, I usually do it in smoothies, and how long will it last compared to other sea vegetables?

    1. according to naturodoc website, chlorella has 600mcg of iodine per 100g (presumably in dried form).
      other companies claim their spirulina has about 500mcg / 100g, while others say theirs has NONE because they don’t add it to their growth medium (water). however it may also have 15000mcg.
      The upper limit for iodine is 1,100 milligrams per day, but an overdose is quite rare.
      The US recommended daily intake for iodine is 150mcg
      these are just some quick google searches worth of information so don’t take my word for it

  35. A quarter gram of kelp is too much? Arame is a type of kelp. It seems that people eat fairly large quantities of this when it’s consumed. So, are they thereby eating dangerous amounts of iodine?

  36. If you eat 0.2 grams or less of kelp a day, wouldn’t it be fine to use as an iodine supplement? Or am I missing something? I’m not particularly fond of sea vegetable tastes, nor is my girlfriend, but I feel like taking a tiny pinky size piece from a dried sheet of kelp would be super easy, and still be right around the daily recommended intake for iodine. Am I missing something here?

    1. I’ve often wondered the same thing. For what it’s worth, here’s my thought: what if the iodine is not evenly distributed? What if some batches are more than others. What if the ends have more or less iodine compared to the part you pinched? When you start talking about taking such small amounts, what if you aren’t really getting the amount of iodine that you think you should are getting? I have no idea if this is a legitimate concern or not. I’m just sharing the thought.

      I have often sprinkled *tiny* amounts of kelp powder in my oatmeal, hoping that this would do the trick. I enjoy nori, but I’m not consistent about eating it. But adding an imperceptible amount of kelp powder to my oatmeal is no hardship. Even though I do it, I have to wonder: am I really doing myself any good?

      I’ll be curious to hear what other answers you get.

      1. Ha, that would be handy if I hand’t bought dried kelp about half a year ago. I take half a pinkie size pieces though, so I’m not worried. Especially because it’s my main source of iodine other than potatoes, and cranberries when in season (not often).

  37. Ups, it isn’t a good feeling when you recognize by your self that the intake of iodine isn’t enough… suddenly my brain was working slowly, I ‘m struggling for some words. It can be very frightening. Ok, god pleas you Mister Greger for this article. But there is still a question inside me.
    is the thought right, that I should take more then the recommend daily intake of 160 micrograms for a while now until the hidden reserves are full again, because I need the daily intake plus that was is going into the reserves or does my brain still not yet working very well again?
    Here in Germany I can take a Wakame soup, each portion has approximately 338 micrograms iodine inside, according to the labor test. good or not Good to take it daily?

  38. Hi Dr. Greger. Thank you for your great and informative videos! I recently had a blood test done and everything was fine except that my doctor was concerns about a slightly under active Thyroid result. She said to do nothing except come back to her in two months to check it again but I was going to try to introduce more Nori to my diet to see if that helps with my fatigue. How long do you expect it takes to regain an normal thyroid function going by your suggested intake of sea vegetables in the above video?

    1. Ringer: I’m not an expert, but for what it’s worth, I think you are very wise to try to add some nori or other sea vegetable to your diet. I’m guessing we won’t know how long it would take to kick in for you, but it certainly can’t hurt to try for at least the two months your doctor wants you to wait and come back. As Dr. Greger is often saying, there’s no downside to trying adding a whole food to your diet in recommended amounts. Good luck. Let us know what happens.

  39. Hi guys I have a few questions, not sure if they’ve been answered all ready..

    1. I’m on a budget and think I’m missing Iodine. I started eating quite a lot of mackerel a while ago and felt better so continued but I think I was over consuming and since learning about how bad toxicity is, and suffering brain fog I wondered if I was getting metal toxicity.. so I want to take seaweed or supplements but wonder if lugols or tablets are better / more affordable?

    2. I can buy some dulse for about £7-8 for 100g here in the UK which isn’t too bad I think, it would be about 75-100 days supply at around 150-200mg daily I think (v rough calculation) but supplements or lugols seem like they could be cheaper, and perhaps especially if one was needing more iodine than 200mg.

    3. What are your personal experiences? Do you find 150mg is enough? does a safe limit vary for smaller body mass? I’m pretty small of stature.


  40. Hi guys I have a few questions, not sure if they’ve been answered all ready..

    1. I’m on a budget and think I’m missing Iodine. I started eating quite a lot of mackerel a while ago and felt better so continued but I think I was over consuming and since learning about how bad toxicity is, and suffering brain fog I wondered if I was getting metal toxicity.. so I want to take seaweed or supplements but wonder if lugols or tablets are better / more affordable?

    2. I can buy some dulse for about £7-8 for 100g here in the UK which isn’t too bad I think, it would be about 75-100 days supply at around 150-200mg daily I think (v rough calculation) but supplements or lugols seem like they could be cheaper, and perhaps especially if one was needing more iodine than 200mg.

    3. What are your personal experiences? Do you find 150mg is enough? does a safe limit vary for smaller body mass? I’m pretty small of stature.

    The site I’m looking at says an entire 100g bag of dulse contains only between 15-55mg of Iodine, which is less than a days supply, conflicting with the information in this video. Can anyone clarify? Are the estimates wrong? I think I’ll go with Wakame (alaria) as I know it has a higher Iodine content.

    The NHS states: (Not that I believe them really..)

    Adults need 0.14mg of iodine a day.

    Most people should be able to get all the iodine they need by eating a varied and balanced diet.

    Helpful as always; am I hearing correctly; 150 mg a day at least? that’s exponentially more than 0.14 mg or am I missing something?? Confused!

    1. You are confusing milligrams (mg) with micrograms (mcg). There are 1000 micrograms in 1 milligram. Micro is usually written as the Greek letter mu, but not all fonts have Greek letters so “mc” is often used. The recommended daily dose of iodine is 150 micrograms per day. 150 mcg is the same as 0.150 mg. 15 mg of iodine would be 100 days worth.

  41. AHHHH, please help. I’ve got two important questions, ore three?
    First: If the serum creatinine low can I be sure that the urine creatinine also is low? In Germany the urine creatinine is measured also for the iodine loading in the body. means, if the secretion of creatinine in the urine is high enough the patient has enough iodine in the body… is that right?
    Second: If the store for iodine empty, would it be not logically that the patient has to increase his intake of daily iodine because the body needs about 200 µg plus a little bit to fill up the store again? And then, if the patient is a vegan and konsum every day Dr. Gregers daily dozen with flaxseed and often broccoli would he need even more to fill up the store again? And what about the article I read in a German medical journal that humans only absorb about 40 % of the iodine intake?
    If I calculate right, I think I need for the next time about 400 µg iodine daily or is my conclusion totally wrong?
    My serum creatinine is since 3 years a little bit to low (about 63 mg/dl) and in the last time I developed strange symptoms. The TSH is still all right and so my physician is not worried – but, I’m honestly – I’m not sure he is the best. :-(
    Thanks for much for a helpful answer.

  42. what about fermented kelp? i have a product that is fermented kelp & chlorella in miso…would this also be detrimental? (i do have hypothyroidism)

  43. Hi! I am from india . I recommend my clients to stop diary and have soy products for healthy weight loss. But i am always doubtful with hypothyroid patients So which food products are good source of iodine . Alaria, Dulse , Laver are not available here. Which are the alternative sources whch we can get in India

    1. Hello Poonam Sharma, I’m from Germany and I have to go in a Asia-Shop to get good seaweed. Your country is much nearer to China, Japan or Korea than Germany – havn’t you no shops running by a chinese or japanese people? What about ordering by internet?
      Here in Germany we have also salt with seaweed inside, a little bit you can get from red radish or also called small redish or white mushrooms but I don’t think you can get there in India.

  44. Dos anybody knowing whether the information of iodine content on a pack of seaweeds pro 100 g seaweed means dried or mean it fresh? Unfurtenally all my packs are from a japanese factury so I’m not able to ask the factory directly.

  45. I’ve been told that we can’t be allergic to iodine and yet when iodine or Betadine is put on my skin I get hives. Before I changed to a plant-based diet I had allergic reactions to shellfish. Any suggestions for getting iodine without an allergic response?

    1. Marta Sprout: Have you tried some seaweed products? Nori is very tasty… You might also research to find out which foods are particularly high in iodine and tweak your diet to include those foods, such as being sure to include lots of whole grains. You can use that tactic combined with the site, cronometer.com, to see if your intake of iodine is already OK from your natural diet and thus supplementation is not necessary.
      I’m curious if you have a reaction when you eat foods fortified with iodine. Maybe you would be fine with lower iodine concentrations from fortified foods?

    1. potassium ratio should be 4 times than sodium to avoid high blood pressure and water retention. so more potassium rich food are better for health. sodium limit most of the time one half teaspoon. Eat lots of potatoes with skin since skin gives some iodine, tomato, banana, and oranges to get potassium. potassium even in access if coming from food will not harm you.

    1. Interesting concept, Pam. I was able to find very little in this non-traditional approach to obtaining iodine.This reference may be helpful:6 selected items – PubMed – NCBI It seems absorbtion of iodine this way involves many barriers, including of course the skin itself. If you have strong iodine exposure to skin you may develop skin irritation. Skin absorption would be very limited evaporating quickly and subject to the thickness of the skin and body’s ability to transport iodine thorughout (as opposed to the much more efficient process nutrient dispersion of digestion. So while you mom’s remedy might seem logical is not practical. Check out Dr. Greger’s video http://nutritionfacts.org/video/avoiding-iodine-deficiency-2/ for a more effective way to avoid iodine deficiency,

  46. In the Netherlands, our iodized salt (“JoZo” means jodiumzout) contains 21 mcg/g of iodine. With a recommended 150 mcg/d of iodine, this leaves us at the need to consume 7.14 grams of salt per day. Wow. Part of that will be in bread, but it still exceeds the recommended salt intake.

    Wakame appears to be of the same intensity as Kelp, though I’m not sure if it’s the same species. At 7900 mcg/g (for dried Wakame, I’m assuming) its ratio is definately higher than JoZo’s, but we’d need to eat 0.02 grams of it per day. A package of 40 grams should be spread over 2107 person.days or 5.77 person.years. Better get some more people in, because its shelf life is a few months only.

  47. Dr. Greger, could you please tell me what would be your recommendations and / or things to avoid while being a vegetarian with Hashimoto’s Disease? Thanks a Million!

  48. i´m from germany so please forgive me my bad english! But i need your help! The problem that i have is hypothyroidism. i´m taking medications for 11 years. They are called l-thyroxin in germany. Is it possible to get rid of these pills, because it sickens me that i have to put these chemicals into my body! I also have side effects because of them (bad mood, depression, fatigue etc.). So i would like to try to live without these pills. The question is how should i stop taking them?

    Can you please help me out of my misery?

    KInd regards


  49. Dear Mr. Greger and team, I’m a bit confused about the iodine. First of all, there is no official information in german language available about the iodine content in Wakame. So my first question is: Have you got any information about the relative iodine content in Wakame? And if you have, is it the iodine content in dried or fresh Wakame?
    Second question – is there a different requirement between a couch-potato and a ambitious sportsman like me – I tried my bicycle about 300 – 400 km per week during the summer time. Does alcohol consumption, coffee consumption also raise the requirement of iodine or is this a myth ?
    I need urgent some answers because my wife and me have only the seaweed for iodine, because we avoid iodine salt and some industrial junk food (also vegan junk food )…
    Thank you for any support in advance – you can also use this email: info@heilpraktiker-jurisch.de

    Have a good week Steffen Jurisch from Germany

  50. Dr. Greger, I’m a 68 year old great-granny and you saved my life, my mind, and my future! Thank you for your videos. I’m losing my hair here recently, been plant-based for 6-months… Recently started B-12… some days it helps and some days it doesn’t? Before I got bald, can you help me?

  51. Is there any other healthy way Not to die from
    iodine deficiency than eating disgusting seaweed or taking supplements?
    This is completely illogical, It is unnatural,
    Most of our ancestors not ate seaweed for lunch, They didn’t supplement iodine also.
    I mean, must be a better way….

    1. Hi Jill, if you’re not getting iodine in your diet from any other source then sea vegetables should be fine and possibly even helpful with Hashimoto’s. Keep in mind that in Hashimoto’s, the underlying cause of your thyroid disease is autoimmune and you body has produced antibodies against your thyroid gland. That being the case iodine may play less of a role in your case but you still need to meet you’re iodine requirement so as I said, if you’re not getting it anyplace else then a little seaweed shouldn’t hurt.

  52. I don’t know if there are better/more recent sources, but the Iodine contents in different seaweed that I found are:
    Seaweed species – Total iodine μg/gDw (mcg/gram dry weight)
    L. digitata 1,886±544
    L. hyperborea 1,946±914
    L. saccharina 1,281±206
    A. nodosum 553±186
    F. serratus 365±31
    F. vesiculosus 494±175
    C. crispus 271±77
    D. sanguinea 110±17
    (source ncbi.nlm.nih.gov via examine.com)

  53. What about other food sources of iodine? I tried to do some searches online and saw that prunes and cranberries also have iodine but less per gram. Is this true? I don’t always like eating seaweed, would be interested to see what other things I could add to my diet to get my daily iodine intake.

  54. How much seaweed is too much? I don’t want thyroid cancer, but I’m concerned about my hormones and weight gain and hair thinning etc, all signs of a deficiency problem.

  55. HI S. Thanks for reaching out. I’m a dietitian and volunteer moderator who helps answer questions. I really like Dr. G’s video “Avoiding Iodine Deficiency” which addresses what types of seaweed to use and which to avoid while striving to meet your daily iodine needs. In short, nori, dulse, wakame are all recommended sources , each small 2 oz bag providing enough iodine for one week, one month or 2 months respectively. The only ones to avoid are kelp and hiziki. The link to the video is: http://nutritionfacts.org/video/avoiding-iodine-deficiency-2/
    Hope this is helpful :)

  56. I have been reading your book and watching your videos related to iodine and thyroid health since I had a blood test back in January that had a TSH result of 16.8, I got retested in March and the score dropped to 6.8, and then I was just retested in May, and it dropped to 3.8, however my doctor also tested for antibodies (two numbers) that came back high. The only thing that has changed over the past four months is that in January they also realized I was deficient in vitamin d and I asked them to test my vitamin b levels in March, which also came back low. So, I’ve been on supplements/shots since February and March for vitamin d and b respectively. At my last visit my doctor said she believes I have Hashimoto’s since the antibodies were quite high (microsomal ab 197 units/mL & thyroglobulin an 4.9) and my TSH numbers are in the normal range now but have fluctuated so much. She recommended simply monitoring and said that ecentually it will develop into hypothyroidism at which point she would recommend meds. I don’t know anyone else who has Hashimoto’s, but a friend told me their mother-in-law was diagnosed previously and went gluten-free in order to “slow down the profession.” I’m wondering if you are familiar with this diagnosis and whether going gluten free or other dietary changes would help. I’m a 27 y.o. white female, and although I have some of the symptoms (dry skin, for example) none of them are new/worsening problems, with the exception of gaining maybe ten pounds over the last 6-12 months, but I’m not sure that counts as significant/unexplained weight gain. Any thoughts you have on supporting thyroid health for those with Hashimoto’s or hypothyroidism would be greatly appreciated.

  57. Hello Alicia,
    Thank you for your question. I am a family doctor with a private practice in lifestyle medicine, and was trained in epidemiology. I’m also a volunteer moderator for this website. I just looked in PubMed (a free database of medical articles), using the search strategy “dietary treatment Hashimoto’s” and came up with some interesting articles, mainly about using selenium supplementation for treatment of subclinical hypothyroidism in patients with Hashimoto’s thyroiditis:

    1) https://journals.viamedica.pl/endokrynologia_polska/article/view/EP.2016.0064/38005: This is a recent Polish study that found significantly improved thyroid function in patients treated with seleno-methionine, as compared with controls. [They used 83 mcg of selenomethionine per day, for 4 months].
    2) BUT, before you run out and buy selenomethionine, be aware that a Cochrane review from 2013 (very prestigious group that pools results from all available studies) was inconclusive as to whether or not selenium supplementation is effective in treating Hashimoto’s: http://onlinelibrary.wiley.com/doi/10.1002/14651858.CD010223.pub2/abstract;jsessionid=7EC23F133473EA5B1377C2B521D1C7E8.f02t01

    Here is a recent Iranian study of Hashimoto’s patients which showed a benefit of treatment with Nigella sativa seed (=”black cumin”). They used 2 gm per day of powdered Nigella sativa, for 8 weeks.
    3) https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5112739/:

    Then, there is a 2015 study from Crete which suggests that supplementation with Vitamin D may be helpful in lowering levels of anti-thyroid antibodies in Hashimoto’s patients (they used fairly standard supplementation with 2,000 to 4,000 IU of Vitamin D3):
    4) http://www.nuclmed.gr/magazine/eng/sept15/07.pdf

    So, given that moderate doses of selenium, black cumin, and Vitamin D don’t have any harmful effects, as far as I know, it might be worth investigating each of these further, and maybe trying them.

    I hope this helps.

  58. Hi Dr. Greger, love your videos and thankful for your work. I was wondering how long does iodine stay in one’s body? Can we take iodine the same way we can take b12 (once a week)? Or do we have to take it every day?

  59. Alicia,

    You should see a physician who is not waiting to treat your thyroid……. The necessary testing should have included both the Free T3 and Free T4 to know what signal your cells are receiving. And I’d wager that your weight gain will be somewhat explained…..never use TSH as your basis for treatment alone……

    One of the best sites and with easy to understand info can be found at:http://sick2death.com/facts-about-thyroid-disease/ You may find it interesting and helpful to some easy testing on yourself…..using the basal body temperature checking.

    For a good overview of the information on Hashimoto’s thyroiditis, which is what your labs suggest, please see this site: Mary Shomon – Verywell Also incorporation of Dr. Jon’s suggestions is in order…..

    Dr. Alan Kadish moderator for Dr. Greger

  60. And what about that “California warning” on the package of dulse, for example? I ordered the brand that’s shown in this video recently, but am most confused and apprehensice because of that little note on the back of the packet that says “This product contains heavy metals known to the state of California to cause cancer and birth defects or other reproductive harm. For more information visit: http://www.seaveg.com/prop65“. Certainly those things would be harmful to anyone, not only Californians :D, but on the site they mention it basically says that you have to make a choice on whether to use it using your own discretion… I’m torn now… I was diagnosed with Hashimoto’s 5years ago after which I went vegan and would like to supplement my plant based diet with iodine safely, not risking other parts of my body… What should I do here? Thanks in advance and also for all the work that is condensed here… Love Nutritionfacts.org and Dr. Greger :)

  61. Hi there,

    A quick Google search suggests that cranberries contain significant amounts of iodine – around 100mcg per ounce. However, I can’t find a reliable source that lists iodine content of foods to confirm this – are you able to shed some light as I’d love to get my iodine intake naturally without relying on supplements or the potential hazards of some seaweeds?

    Many thanks in advance!


    Ps. I first heard Dr Greger on the Rich Roll podcast – love what you do!

  62. I too did a thorough search for iodine content of cranberries because like you, I wanted to verify and enjoying eating them knowing I was getting needed iodine. Alas, while a source listed them (as well as navy beans, and baked potatoes with skins) as having high iron content, that source did not provide a reference and when I searched through reliable data bases, all I found were the following listed as good non fish,meat/diary/egg sources of Iodine:


    Corn, cream style, canned, 1/2 cup 14mcg 9% DV (Daily Value)
    Prunes, dried, 5 prunes 13mcg 9%
    Raisin bran cereal, 1 cup11 mcg 7%
    Lima beans, mature, boiled, 1/2 cup 8 mcg 5%
    Apple juice, 1 cup 7mcg 5%
    Green peas, frozen, boiled, 1/2 cup 3mcg 2%
    Banana, 1 medium 3mcg 2%
    A British dietitian data base also listed these as high iodine foods:
    Nuts 25g 5mcg
    Bread 1 slice (36g) 5mcg
    Fruit and vegetables 1 portion (80g) 3mcg

    Since the recommended DV is 150 mcg, you may find it may be challenging to obtain that amount without that seaweed Dr. Greger mentions. Perhaps this report might be reassuring on that score: https://www.ncbi.nlm.nih.gov/pubmed/26817952 It concludes:
    Total As, Cd, and Pb concentrations ranged from <1 to 67.6, to 7.2 and to 6.7 mg/kg(dry) respectively; therefore, their contribution to total elemental intake does not appear to pose any threat to the consumers, but the concentrations of these elements should be controlled to protect the consumer against potential adverse health risks.
    Hope that's helpful.

    1. Joan, Thank you for responding to my question.  There are really 2 issues.  One is finding sources of iodine.  You provided useful information on sources of iodine.

      The more important questions is, “What/where are reliable sources for nutrient information for food?”
      As I mentioned, I searched the USDA data base (via http://nutritiondata.self.com/facts/fruits-and-fruit-juices/1875/2 but the iodine field is blank for cranberries. 

      So, the important question is, where can I find a comprehensive database with complete nutrition information. 

      I find it difficult to believe that there is no comprehensive database with complete nutrition information for virtually all foods normally consumed.   If it is not accessible to the public, then why?  It does not appear from your response that you have access to this information either. 

      Thank you. Brooks

  63. If I don’t want to eat sea vegetables or iodized salt what are the other options? Is a potassium iodide supplement every day @ 150mcg safe to avoid deficiency? I do not take a multi vitamin anymore, only b12 supplement. Plus I eat flax, broccoli and soy which doesn’t help the iodine situation. Thank you!

    1. yogurt is good source of iodine according to national institute of health. dairy , bread , egg yoke are rich source then some u get here and there. Have to search on cranberries from reliable source. potato skin, strawberries, can beans , chocolate, rice have some but not significant amount of iodine. iodized sea salt just 1/4 spoon provide 47% of daily requirement. rest u can get from yogurt . But how do u know you are deficient in iodine. may be try random urine analysis to get idea of status. since too little is bad too much is bad.

  64. Should I still take the recommend dose of 150mcg if I eat a lot of potatoes and some broccoli? I eat NO sea vegetables and do NOT add iodized salt to my food just for the record.

  65. Hi Dr. Greger,

    I just wanted to follow-up on Kotryna’s questions from June 2, 2017 regarding dulse and the product-specific California warning that reads: “This product contains heavy metals known to the state of California to cause cancer and birth defects or other reproductive harm”.

    My wife and I currently follow your daily supplement recommendations, including using dulse as a primary source of our intake of iodine.

    Could you please take a look and let us know your opinion on the quote above? Would you recommend to continue or discontinue use of said product? In addition, would a whole-food plant-based diet (i.e. in line with your recommend daily dozen) offset the outlined risk from the heavy metals?

    Thanks for your help.


  66. Hi Dr. Greger,

    Thank you for all your work.

    I wanted to follow-up on Navjit’s question on Sep. 5th. regarding dulse and the product-specific California warning that reads: “This product contains heavy metals known to the state of California to cause cancer and birth defects or other reproductive harm”. Would you recommend to discontinue consumption of products labeled with this warning message? I am having a hard time finding alternative dulse producers that do not have the warning, if there is any brand you can suggest I would greatly appreciate it.

    Thank you


  67. Hello I would just like to know, if possible, how much in grams a sheet of nori is please. Dr Greger recommends 1 sheet a day but packets come in various sizes.
    Many thanks

  68. Hi. I have a question regarding using Dulse as a source of iodine instaed of iodized salt. In Dr. Greger’s Book he mentions that half a teaspoon of dulse is enough to meet our iodine needs. But half a teaspoon of dulse is only about 75mcg of iodine, according to many sites including maine coast sea vegetables that sells dulse flakes, on average it takes 1 gram of dulse flakes to get 167 mcgs of iodine.

    So shouldnt the recomendation be a full teaspoon? or was Dr Greger leaving the missing 75mcg to get from the plants we eat? What if those plants dont have it?

    Is it ok to eat a full teaspoon of dulse flakes everyday as a source of Iodine if one doesnt use iodize salt and leave far from the coast where plants are less likely to have iodine?

  69. Thank you for your question. Dr Greger recommends 150mcg of iodine a day so yes, if the pulse you are buying is less concentrated then would would need more. 1000mcg per day seems to be the upper limit that is safe so a whole teaspoon would not do any harm.

  70. Should the dried seaweeds be rinsed with water to clean them before eatting, or just them like that? Im not sure if the iodine would stay or not?

  71. How much nori / laver seaweed should I eat per day to get the daily recommended intake? 2 large sheets for making sushi rolls? or maybe 2 of the seaweed snack packets of the smaller size squares? I can’t find the answer anywhere on the site. Thanks!

  72. Hi, Jefferson. Different types of seaweed provide varying amounts of iodine. The label on a canister of dulse granules with garlic that I have on hand specifies that a 1 tsp (2 g) serving size provides 170% of the Daily Value (DV) for iodine. The DV for iodine is 150 mcg. This means that a teaspoon a day of dulse should more than meet your iodine needs. As noted in the video, Dr. G. does not recommend kelp, because it may provide too much iodine, and too much can be as bad as too little. Nori has more vitamin b12 than many other seaweeds, but much less iodine, at about 16 mcg/g. Dulse may be your best bet as an iodine source. I hope that helps!

    1. Thanks so much for the quick reply. But I’m asking about nori / laver, seaweed sheets that wrap sushi. Should I eat 2 large sheets for rolling up a log of sushi or 2 of those little squares that come in a seaweed snack pack?
      Thanks again!

  73. Hi, Jefferson. Nori is not the best thing to eat for iodine. Go ahead and use nori to wrap your sushi, if you like it, but there are better sources for iodine. Rather than eat more nori, I would choose other seaweeds for iodine. Dulse flakes may be sprinkled on food like a seasoning, and add a dose of iodine. If you still want to try to meet your iodine needs with nori, then using the information from the video, you could take the number of sheets in a package and divide by 7 to get the number to eat per day, based on the idea that the package provides a one-week supply of iodine. That is my best answer to your question, and I hope it helps!

  74. Dear volunteers,

    Thank you very much for al the helpful information! If I’m not mistaking the conclusion could be that the best solution is to eat Dulse to get enough iodine when following a plant based diet if you want to avoid taking supplements or using iodized salt?

    Thank you very much for your answer!

  75. Hello Elisa!

    Thank you so much for your comments. As Dr. Greger said, there’s a lot of safe options to meet your iodine requirements if you want yo avoid iodized salt. Nori, dulse, wakame are all recommended. So, if you want to use dulse, it’s a great and safe solution!

  76. I have been using Dulse flakes from Maine but I am still unsure if I am using the correct amount.

    I have read all the studies I could find that mentioned iodine concentration in dulse(palmaria Palmata) and there is no consensus. Of course there is vation because of it being a whole food but when we want to use it as our source of iodine what should be the correct amount?

    Most sources I find say that it has on aveg 75mcgs/gram. one teaspoon has about 1 gram in the dulse flakes I bought from maine.

    So if I go by that number I should consume 2 teaspoons right? But Dr Greger only mentioned half a teaspoon in his book and I am unsure if he meant every day or every meal.

    While other studies say it has about 150 mcg/g and the package of the dulse I bought says it has about 167 mcg/gram. Should I just trust the label when I see studies saying different numbers?
    If so then 1 teaspoon should be plenty or should I am for below the RDI and hope the food I eat has some? I live far from the ocean where the soil has more iodine in the soil.

    The most recent study I could find: Iodine content in bulk biomass of wild-harvested and cultivated edible seaweeds: inherent
    variations determine species-specific daily allowable consumption, Food Chemistry (2018)

    Say that samples from the east shore of the north Atlantic ocean range from 72 to 293. Average: 183mcgs per gram.

    So yea based on everything I mentioned I have no idea how much I should use and safely meet my RDA of iodine with dulse flakes.

    So far I have been using 1 teaspoon. Half a teaspoon with lunch and the other half with dinner. Using a measuring spoon.

    1. Oh and I dont want to go too far above the RDA. The upper limit is 1000mcgs but that is also not the consensus. Some say that it should be kept below 400, 500 and 600 depending where you read.

  77. Thank you for this video, but I have a few concerns.

    First: Sea vegetables contain B12 analogues that lead to B12 definciencies.

    Sea Vegetables have been proven to contain considerable amounts of heavy metals. Should we really take this stuff on a regular basis? Why not just take 100ug -200ug of pure iodine in tablet form. I love the whole food approach but maybe in the case it might be safer.

    I also think that it maybe iodine, that is the main reason why paleo works for some people. Dr. Klapper and Mc Doughall both recommend Iodized Salt, but I don’t want to eat salt, so again , why not recommend the pills which contain the same amount and form of iodine that is added to salt in a much better controlled dosis.


    Since cruciferous vegetables massively intefer with iodine uptake, the recommended dosis may lead to a severe insuffiency on the plant based whole food diet. I would like to know, if a timed intake of iodine away from cruciferous vegs may work here. For example only take your iodineon days when you do not eat cruciferous vegs. May this work?

    I’m very concerned about iodine after this very good article, iodine may be a key to todays deseases:


    1. One thing I forgot:

      I read that parsley contains 160ug of iodine per 100 grams, spinach: 164μg. Is that true? I would be the daily minimum value. Maybe this could be a natural alternative to sea vegetables?

  78. I think, this discussion is a bit off track. I seems, we don’t even know how plant bound iodine or say animal bound iodine is metabolized by our body. Do we know if potassium iodide can be converted by our body at all to be used later for our organs and tissues, or is it maybe just used for our thyroid and hormon production? Does potassium iodide fed to animals go into their tissues and other organs? This may indicate, that a potassium iodide supplement has the same effect on humans and we would not have to eat sea food to cover our needs. Maybe plant bound or meat bound iodine does not go through the thyroid at all and is instead used directly for our other cells and organs.

  79. In a review of three clinical trials, which determined the response of patients with FBD (fibrocystic breast disease) to different forms of iodine, researchers reported molecular iodine was superior to protein-bound iodide and sodium iodide when treating FBD.16 In one study, 74.5% of the women with FBD treated with 0.08 mg molecular iodine per kilogram showed improvement with microcysts disappearing within five months.16 Other forms of iodine were less efficient and included side effects such as iodine poisoning (iodism) and acne.16

    16. Ghent WR, Eskin BA, Low DA, Hill LP. Iodine replacement in fibrocystic disease of the breast. Can J Surg. 1993;36:453-460.
    14. Aceves C, Anguiano B, Delgado G. Is iodine a gatekeeper of the integrity of the mammary gland? J Mammary Gland Neoplasia. 2005;10:189-96.
    17. Venturi S. Is there a role for iodine in breast diseases? The Breast.

    I’m not a researcher and lack all chemical knowledge, but can somebody please tell me, which form of iodine is the one mentioned to have positive results and which form of iodine can be found in meat (just curious) an which form we can get from sea vegetables? Everybody is just talking about iodine, but there seem to be many different form with very different effectson the human body.

  80. What the heck is molecular iodine l2 ?



    “While the application of iodine supplementation has long been recognized in clinics, treatment effects have not been effective because iodine supplements in the market are either unstable or contain iodine salts, both of which are proven to be ineffective and have strong, undesirable side effects. Only molecular iodine (I2) …

  81. Hello J. I’m a health volunteer moderator here at NF.org

    Yes, you’re right, just like almost all the nutrients, iodine has many forms too. It basically depends on the source it is found, moreover, the iodine content of food depends on the iodine content of the soil in which it is grown.

    NaIO3 = Sodium Iodine
    NaIO4 = Sodium Periodate

    Seaweed / Algal Phytoplankton
    KI = Potassium iodine
    NaI = Sodium iondine
    I2 = Iodine

    There’s also another form found on seawater named as Iodide.

    Once you’ve ingested iodine from the dietary sources, it is converted in iodide: “Iodine from the diet is absorbed throughout the gastrointestinal tract. Dietary iodine is converted into the iodide ion before it is absorbed. The iodide ion is bio-available and absorbed totally from food and water”

    You can also find more info about iodine here:

    Iodine on NF.org


  82. Thank you very much indeed for your reply!

    I’m sorry, but I am still at loss to understand this, maybe I lack iodine in mybrain:)

    So does this mean, I get exactly the same form of of dietary iodine from sea vegetables as I would from supplementation with isolated potassium iodide? Did the studys mentioned above use a different form of iodine that was not orally administered? Or why do they make such a great distinction?

    Quote: “researchers reported molecular iodine was superior to protein-bound iodide and sodium iodide when treating FBD.16”

  83. As far as iodine goes, there seems to be a lot of confusion, especially when it comes to the content of iodine in plants. At the same time, I really don’t understand why milk and eggs are supposed to be a good source according to some experts. Milk: 10 ug, Eggs 8ug, “Leeks 8ug”, the same goes for treated salt unless you eat a spoon per day. Spinach is also recommended as a source of iodine by some experts even though it is said to be goitrogenic, even radiccio is said to be goitrogenic, what kind of leafy green vegetables other than salad remains for my daily smoothie that one can eat on a daily basis that fills you up with nutrients if all cruciferous vegs are out of the equation? And that is another point, nobody seems to know how much iodine is killed by how much goitrons, there is zero research, yet people make recommendations. That’s not science. Is there any study that shows, that 150ug from dulse is sufficient to cover the needs in a WFPBD that consists of many goitrogenic leafy greens? I know a lot of people who eat cruciferous everyday, just like Dr. Greger recommends. What if they all end up bad after a few years due to iodine insufficiency?

  84. Have my doubts about Dr. Brownstein. He recommends 5-10 grams a day of buffered vit. c–Doc says 200 mgs. is all body will absorb.
    Dr B says avoid soy at all costs–
    Dr B says take iodine (not sure of rec. amount.)Ill stick with Dr. Greger.

    1. I tookDr Brownsteins advice as I was hyprthyroid and took iodine, it gave me a thyroid goitre and made me hyperthyroid which is much more dangerous!
      If you take iodine have blood tests done every couple of months, or eat kelps etc instead.

          1. His recommendations opposite of Dr. Gregers–as per my original response.
            Not to mention, he sells supplements on lots he recommends–just my thoughts.

  85. I realize this is an older video, but I’m hoping Dr Greger will see and address my question here. I am a plant-based health coach, fitness trainer and herbalist who refers people extensively to nutritonfacts.org and draws on Dr Greger’s accumulated research and authority to support much of my own teaching. This is my #1 favorite resource and it becomes that of many of my clients as well.

    I came on this video today however searching the database for information on the relationship between low thyroid and elevated cholesterol, which is pretty well established for obvious reasons if one understands the biology and metabolism of the making of thyroid hormone. I have been vegan for 4 years, was vegetarian/pretty-near-vegan for 20-some years before that. But I’ve tended toward low thyroid all my life (even before being veg). I have managed it without drugs and am asymptomatic except for somewhat dry thin hair (eg I don’t “present” as low thyroid, as more than one doc has put it—I’m lean, energetic, skin is great, not depressed, ony tired when i dont sleep, etc). My feeling: this is what low thyroid looks like when you’re otherwise super healthy and take amazing care of yourself. :) In spite of the wild disagreement about it, I have pretty much thru my own research dismissed the notion that I shouldn’t eat cruciferous veggies or starchy fruits/tubers/veggies. I’m also *not* gluten-free (I dont overload on it, and really eat pretty little grain overall, but I do eat toast for breakfast ;) ) because my thyroid does NOT happen to be the autoimmune kind (always negative for antibodies). I use herbs, botanicals, vitamins, minerals and other supplements to manage this naturally. And of course other healthy practices from exercise, good sleep and meditation to organic and toxin-free products etc.

    When my thyroid dropped below a certain level about 6 years ago (it’s still in reference ranges, but T3 and T4 near low end of range—TSH is in middle, just under 3 so just barely clinically hypo) my always-naturally-low (165-ish total) cholesterol jumped to 210-215 total (LDL 119-139, HDL 72-82, triglycerides 52-59, VLDL 10). It’s hung there since, never moving much from the above even as I went from vegetarian to vegan. Clearly, this is the inverse thyroid/cholesterol relationship. Given all other factors I think my heart disease risk is way low (high HDL, low blood sugar ,low blood pressure, low A1C, low bodyfat, plenty of exercise, plant-based diet, of course no smoking)…but is there any reason to be more aggressive about this? i think i’m more borderline than high, and I do think more recent research shows that cholesterol as an independent factor isn’t that meaningful…

    Another thing that would be great to address in a video: As you are probably aware, there is much info on the interwebs about how if you have low thyroid, you have to eat meat, otherwise can never get the nutrients you need to heal. I don’t believe this, but I would love to hear Dr Greger’s views and research. There is so much astounding info and value in this database, but there is no info as yet on thyroid and meat, thyroid and plant-based, thyroid and cholesterol. A series on this would be FANTASTIC, as low thyroid is obviously an epidemic and if we want people to be plant-based and so many are low thyroid and they only hear that vegan will make them worse..it would be great to clear all this up. I see a lot of people who have subclinical low thyroid or worse. I would like to help them ad share what i have done to manage this so naturally, but many come with the belief that they must eat meat to get better.

    I would also like to know what more i can do to help myself and other people other than take tyrosine, guggul, ashwaghanda, selenium, zinc, and other botanicals and minerals. It would be great to hear your thoughts on glutamine and glutathione and the most bioavailable ways to get these without meat, and how much difference that could make.

    A note re this video: unlike may people, i respond well to Iodoral—a lot of it! and it doesn’t make me jittery like it does some people. I’m curious about this concern re EXCESS iodine as apparently I can handle a lot of it. Is it REALLY possible to get too much, especially if you’re low thyroid and not Hashimotos? If i’m responding well to Iodoral, could i really possibly eat too much kelp?

    Really hoping Dr Greger can make this into another one of his great series! Thank you!

  86. Hello Robyn, and thank you for your great questions and comments,
    Your question caught my eye because of my own recent experience with presumed iodine deficiency (more about that in a minute). I am a family doctor with a private practice in lifestyle medicine. I have only been completely vegan since 9/2015. Like you, I use Dr. G’s website and videos extensively in my practice (see my website below), and have bookmarked over 200 of his videos, organized by topic.

    I went vegan mainly because of my cholesterol: LDL was up to ~170, and small LDL particle count about 1350. I also had borderline high blood pressure, for which I’ve been on a low salt diet for about 30 years. So, last time I checked cholesterol levels in Jan of ’17, my LDL was down to the 90s, and small LDL particles were “<90"! My BP averages about 130 systolic, on no medications. Well, then starting maybe 3-4 months ago, I began noticing fatigue — mainly with running. I run about twice a week, usually about 3 miles. I have always loved running on trails; used to run a lot more, including a marathon in my 20s (am 63 now). In retrospect, I now realize I also was noticing cold hands and feet much more than usual, and my skin has been drier than usual.

    This fatigue was very unusual: I was having to force myself to run, when it always used to be so easy and pleasant. (I am in good shape, BMI of 21). It suddenly occurred to me one week ago, that I might not be getting enough iodine. I don't add any salt to my food, and avoid all salty foods, and am good about not eating any meat, dairy, or eggs. My only supplements have been B12, D3, and recently algae-derived DHA/EPA. I just wasn't thinking about iodine, even though I've referred a number of people on this website to Dr. G's short list of recommended supplements: https://nutritionfacts.org/2011/09/12/dr-gregers-2011-optimum-nutrition-recommendations/.

    So, yesterday, after one week of taking potassium iodide supplements (225 mcg), I went for a long run, and my energy was mostly back! I have not even bothered to check my iodine level nor my TSH nor other thyroid tests. (I'm kind of a minimalist about lab testing; in fact, I've never had my thyroid levels checked).

    Enough about me. Your questions are:
    1) Should you be "more aggressive" in treating your mildly elevated cholesterol levels, given that all your other cardiac risk factors are very low?;
    2) Do you, or other people with low or borderline low thyroid function need to eat meat in order to "get the nutrients you need to heal"?;
    3) Do you/ other vegans need to take "other botanicals and minerals"? (You mention tyrosine, guggul, ashwaghanda, selenium, zinc, glutamine and glutathione)
    4) Is it possible for you/ others with low/ borderline low thyroid to consume too much iodine — via supplements and/or kelp?

    1) Your cholesterol levels: given that your LDL is usually below 130, and your LDL/HDL ratio is great, and your absence of any other cardiac risk factors (although you don't mention anything about family history), I would absolutely not recommend that you consider taking medication to lower your cholesterol — if that's what you mean by being "more aggressive". However, maybe your real question is whether or not you should consider taking supplemental thyroid hormone?

    It is pretty well known that hypothyroidism can cause elevated cholesterol. Here is a reference about that, from a quick Google search: https://www.nahypothyroidism.org/high-cholesterol-low-thyroid/. You are probably aware that there is a lot of disagreement, even among endocrinologists, about so-called "sub-clinical hypothyroidism" (SCH). My own experience as a family doctor for almost 30 years is that this is a real disease, with identifiable consequences. The definition of SCH is "a serum thyroid-stimulating hormone (TSH) level above the upper limit of normal despite normal levels of serum free thyroxine." Here is a very good review article about the subject: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2664572/.

    My own practice has been that patients with a TSH above 3.0 (maybe even 2.5) can sometimes benefit from low dose thyroid replacement. I must admit that I have not done much testing for iodine deficiency in the past. That will now change!

    2) Regarding whether ANYONE needs to eat meat in order to get the nutrients they need to heal: I think Dr. Greger's videos have pretty much answered that question. I certainly don't think so — as long as people take the short list of supplements recommended by Dr. G (see the above link in 3rd paragraph).

    3) Do vegans need to take other supplements? Certainly there are other minerals and nutrients that are important to health, including zinc and selenium. But I strongly believe that if you eat a balanced, whole foods plant based diet, you will get all the nutrients you need. It's always possible that new evidence will come to light showing there are other supplements we need, but I certainly am not aware of any at this time.

    4) Is it possible to take too much iodine? Obviously the answer is yes. Here is a link to an article I just found by Googling "iodine toxicity": https://www.healthline.com/health/iodine-poisoning. This says the upper limit for adults should be 1100 mcg per day. If you take Iodoral daily, then you're getting 1250 mcg per day. The link I just gave about iodine poisoning notes that Japanese people consume 1000 to 3000 mcg of iodine per day, mostly as seaweed. However, the rate of hyperthyroidism is much higher in Japan than in the US — although their life expectancy is also much higher!!

    I know that taking 225 mcg per day of iodine seems to have cured my fatigue. I am, as always, humbled by how much I don't know, or don't remember, about medicine, even as it concerns my own health. Good luck in pursuing your own answers. I hope this has helped!

    Dr. Jon
    Health Support Volunteer for NutritionFacts.org

  87. Hello! I’ve been vegan for 1,5 years and got a concern.
    Does soy protein isolate (90% protein) contain goitrogens?

    I eat quite a lot of soy products and consume 20 g of soy protein isolate 3 times per day (I’m weightlifting).

    Recently I did a blood test and it has shown elevated TSH level of 5,2 mE/L. I’m suspecting that I’m low on iodine so I started with 150ug iodine daily. I normally use iodised salt but the amount seems inconsistent. The same goes for seeweed.
    In three month I’m planning to do another blood test.

    1. The whole iodine issue is a big problem in my view, nobody seems to know anything, puts the whole veganism thing into question as far as health is concerned. Don’t let anybody tell you something, the truth is, we don’t really know anything, it is all good guessing.

      —–Original-Nachricht—– Betreff: Soyboy commented on Avoiding Iodine Deficiency

    2. Soyboy: I’m no soy hater but you’re consuming far too much soy protein per day. Greger highlighted a paper that showed the max safe dose was 5 servings per day. Using the study’s protocol of calling a cup of soy milk (7g protein) 1 serving, this means 35g soy protein is the absolute max you want to go.

      I suggest mixing up your vegan protein sources with hemp and especially pea protein.

      Re iodine, IIRC the tolerable upper limit per day (TUL) is only 800 mcg, micrograms. Keep that in mind when dosing, and please talk to your doc about the TSH level.

  88. I was hypothyroid, so followed dr Brownstein s advice and took a few drops of lively a day. Within a few months I was hyperthyroid, which is v dangerous as my heartbeat was far too high, often raced for hours,sometimes became very irregular, and could go into a thyroid storm which can be fatal. I am now talking THYBALANCE, A HOMEOPATHIC preparation, to keep it inder control. Please do not take iodine drops, take kelp,Celtic sea salt, or sea food, and get your bloods tested every 3 months at least.

  89. Hello,

    I read the entire book How Not To Die and I have learned so much. I have not ever felt better in my LIFE! so thank you. I do have one question though, you discuss using Seaweed for Iodine and even show the packages but you dont show how much to use that a normal person can identify and utilize. 150mcg is great, but how much is that is a day to day usage like sprinkled on a salad of say Dulse or Laver? Teaspoon, 1/4 teaspoon, 5 flakes, 2 flakes, what? Please help as I dont want to get too much. Thank you.


    1. Hi there rwmission, thanks for your comment.

      The DV for iodine is 150 mcg. This means that a teaspoon a day of dulse should more than meet your iodine needs.

      Hope it helps!

      1. It actually doesnt because of many reasons. In Dr. Greger’s book he doesnt state any measurements at all to follow. As I understand it lack of iodine is critical, but too much can do some serious damage including lead to Cancer. So putting a measurement followed by the word “should” does not give me much confidence at all. Dr. Greger put in his book measurements for everything and then we get to that one piece and no measurements. That is disconcerning. Not even a brand that he would use as a supplement. I do not wanna take my life in the hands of a “Health Support Volunteer” that uses a measurement followed by the word “should” no offense. I would prefer a doctor or Dr. Greger reply to give the measurement for the seaweed that would equate to 150mcg, someone that can confidently say that. I also hear that laver is less risky than dulse also, so am wondering why you chose dulse when I identified them both in my comment. If you cannot provide that how about at least a brand or 2 of supplements that supply iodine in the 150mcg amount that Dr. Greger prefers, as he mentioned brands in the book also, but again got to that part and nothing. I am just wondering why he chose one of the most dangerous areas to not say much of anything on it and not any other area of the book. So I need a more informed and knowledgeable person to respond to my original comment.


      2. Its a GREAT thing I did NOT take Janeth’s advice of the amount of seaweed. Look up mcg to teaspoon conversion and when you put in 150mcg it comes to 0.0000299999999999999 teaspoons! I check three different sites! This is the issue and a MAJOR one! Janeth you will make people sick if you give them this advice, you should not be giving advice like this if you are not sure these are lives you are dealing with! I still need a proper amount or a supplement that is reliable preferably by a doctor.


  90. Hi. If anyone with medical knowledge could weigh on on this it would be immensely appreciated. I’m a 30-year-old male and I was recently been diagnosed with Subclinical Hypothyroidism, which upon researching, is possibly caused by an iodine deficiency; succinct with what Dr Greger is saying here. I have been Vegan for nearly 4 years now so I’m concerned that my prior lack of knowledge surrounding this has lead me to this point. I have been prescribed Levothyroxine which has brought my thyroid levels into balance. However, when discussing the options beforehand, I asked if introducing more iodine into my diet might be an option and told unequivocally no. I am also to believe that this is irreversible and I will have the condition for life. The cynical side of me doesn’t trust healthcare professionals, and if it wasn’t for the fact that I don’t actually have to pay for my prescriptions, (because here in the UK if you have one of a select few conditions that are apparently no fault of your own, you get free prescriptions for life), I would think they just wanted to keep me on meds. So my questions are; Is it likely that this was caused because I’ve not been getting enough Iodine since becoming Vegan? Is this for want of a better word, ‘curable’? and is it manageable without the use of drugs? Thanks

  91. Hello Zac,
    You have an excellent question, and I think I can help. I’m a family doctor with a private practice in lifestyle medicine, and also a volunteer for this website. I am personally interested in this topic.

    Here is my story, briefly. I’ve been completely vegan for about 3 years now. I also have had “high-normal” blood pressure for many years, and so have really tried to avoid salt. I occasionally have salt cravings, and might eat a few “lightly salted” tortilla chips, but these days the chips I buy are generally salted with “sea salt”. So the point is that I get very little iodized salt in my diet. And I was getting almost no iodine from other food sources. I’m a runner, and beginning about a year ago, I began to notice always feeling fatigued soon after I started to run. Finally about six months ago, when my wife got worried about me, I did some research, and realized I might be iodine deficient. I never got tested (now I wish I had done that), but just started taking an iodine supplement — 225 mcg per day of potassium iodide. After about 10 days or so, the fatigue vanished and hasn’t returned.

    I have a master’s degree in epidemiology, and know very well that anecdotal evidence like I’ve just presented to you should not be given too much weight, compared with scientific studies. However, you can look on PubMed (a free database of medical articles), and there are many articles that link low iodine intake with subclinical hypothyroidism. Here are a few examples:
    1) https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5543254/ — full text link to recent article about mothers and babies in northern Norway.
    2) https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5484247/ — full text link to meta-analysis of 43 studies from China; interestingly, these studies showed that subclinical hypothyroidism could also be caused by too HIGH intake of iodine — although high iodine intake more commonly leads to HYPERthyroidism.
    3) https://www.ncbi.nlm.nih.gov/pubmed/25591468 — link to a great review article in Lancet called “Iodine deficiency and thyroid disorders.” You can register for free with Lancet to get a link to the full text. I did that, and it turns out that the story is complicated but they clearly state that “Severe iodine deficiency causes hypothyroidism because, despite an increase in thyroid activity to maximise iodine uptake and recycling, iodine concentrations are simply not high enough to maintain thyroid hormone production.”

    So, I am pretty convinced that in my case, iodine supplementation cured what was probably a hypothyroid state that led to fatigue. Note: I also had other symptoms of hypothyroidism: dry skin, and increased sensitivity to cold, which have also resolved.

    If it were me, I would start taking an iodine supplement. 150 mcg per day is sufficient (I take 225 mcg only because I wanted a vegan capsule, and found one made by “Pure encapsulations” that was also inexpensive). Then I would wean slowly off of the levothyroxine. However, I recommend that you consult with an endocrinologist before doing this. I don’t know your whole medical situation, and cannot give you good advice in this setting.

    Health Support Volunteer for NutritionFacts.org.

    1. Hello Dr, thank you for taking the time to reply and share your experience. It’s interesting that you mention that you suffered from dry skin and increased cold sensitivity as I have also, but for as long as I can remember and whilst I wouldn’t say I feel fatigued often, I don’t ever feel particularly energetic, and do suffer terribly with exhaustion after intense exercise sessions. Hard to say if it’s related or not. I am tempted based on this advice to consult with my GP again and ask for a test specifically for my Iodine levels to see if they are low which would obviously support the possibility. Whilst I’m willing to try iodine supplementation I worry about having too much as it’s still an unclear subject from what I’ve read. Also, I would also rather get it naturally from my diet on an ongoing basis.

  92. This subject needs to be extensively revisited. I would love to hear Dr Greger’s opinions on iodine shortages in today’s US population. Of course I know Dr Greger does not use opinion and that’s what I love about him BUT … it seems clear to me from my own personal experiences and those of so far, almost everyone I know that there is a serious shortage of iodine in the general population which is maybe at the center (and most certainly is big influencer) on digestion, weight control, exhaustion, dementia, hypothyroidism, etc.

    There has been a interesting info floating around the Net about taking an iodine level test. Not the typical iodine loading test which requires that you digest 50 mg of iodine (WTF?) but rather a simple test where you take 2% tincture (simple common drug store stuff, under $5) of iodine and draw either a square or circle on your skin. Sizes vary but it seems that size is not so important. Circles, squares, 2″ or 3″ in size will allow you see how fast your skin absorbs it. Maybe people do not know but your skin is great at absorbing all kinds of minerals from magnesium to iodine to boron, etc. Anyway if this mark is gone within 12 hours you are said to be somewhat deficient. The sooner it’s gone the more deficient you are. Mine disappeared within 5-6 hours.

    Since supplementing with 1 mg iodine capsules (Sea Iodine from LEF) I can get this spot to stay on my skin longer. The effect is almost immediate and if I skip a day and a half, I am tired in the afternoon and my thinking isn’t as clear It’s astounding and since I’ve told friends about this most have also tried it with similar effects usually. I do have one friend that does eat a lot of fish and he’s pretty much right on the 12 hour window so he seems fine. Many many others though are as deficient as I am. BTW it takes a long time apparently to replenish your iodine stores. Obviously most of this is pointing to the hormone reductions from the thyroid. The daily suggested intake for iodine seems to be WAY off to the detriment of our entire society. Oh, and one last thing .. I had been taking 1 mg of iodine every day for a decade before this showed up, and that wasn’t enough to keep my iodine stores at decent levels.

  93. I recently purchased kelp tablet supplements so that I can receive my iron since I’m unlikely to consume sea vegetables on any frequent or consistent basis and I avoid table salt to keep blood pressure down. I see that Dr. Greger says to avoid Kelp because it contains too much iodine, but the tablet bottle says each one is 150 mcg of iodine from from kelp. So can I assume this is safe since the iodine level from the kelp is measured or do you still recommend I do not take the kelp? Thanks so much for your help. Reading your book has changed my life and I’m forever thankful for the work you do.

  94. Chris,

    I would recommend that you adhere to Dr. Greger’s suggestion that you avoid the kelp supplementation.

    The lack of quality control could put you at risk for either a false sense of adequacy or an overt higher than appropriate supplementation. Please see my recent article and two new findings regarding supplements and their lack of consistency at: https://centerofhealth.com/faking-supplement/ .

    One of the issues with iodine supplementation is the lack of a well-established validated laboratory test to evaluate your unique body’s needs.

    May I suggest that you consider occasionally working with some nori, a seaweed that can be versatile and tasty without a whole lot of preparation ? Making some veggie rolls is both fun and gives you a dose of iodine.

    Good move on the salt restriction and keep on finding the diet components that work for you.

    Dr. Alan Kadish moderator for Dr. Greger http://www.Centerofhealth.com

  95. Hello I have a question regarding iodine deficiency. I have been vegan for 3 years and have been trying to improve my health every day since. I’ve been having a lot of stomach related health issues over the last 2 years and have been diagnosed with hypochlorhydria. I have had no luck from my doctors in finding the source of this sudden onset of low stomach acid (I’m only 21 as well) and I can barely digest anything. Food just sits in me for hours and I am not able to eat enough everyday as a cause of this. What I have deduced from a lot of research I have been reading is I could be Iodine deficient. I gave up all salt in my diet about 2 years ago before I had any stomach issues, and I have had several blood tests to rule out other more common deficiencies and everything has come back normal. I do not eat any sea vegetables and the multivitamin I take has no iodine in it either. I have had my thyroid checked however, and I do not have any issues there either. So my question is, could iodine deficiency cause low stomach acid, and could someone be iodine deficient and have a normal functioning thyroid? Sorry for the long comment. Thank you for your time and I hope you have a wonderful day!

    1. Hi- The best test for iodine deficiency is a urine test that is readily available. You can have iodine deficiency without yet having thyroid problems, but as iodine is crucial for making thyroid hormone, iodine deficiency is a precursor to an underactive thyroid gland. This often shows up a a “goiter” or lump in the neck. The blood tests seem to show that right now you do not have thyroid deficiency. If you have iodine deficiency by urine iodine test, iodinated salt, sea plants, or an iodine supplement can take care of this.

      It’s important to point out that hypochlorhydria, or insufficient stomach acid, should be diagnosed by a gastroenterologist (GI) using a direct measure of acid in the stomach. There are several ways to do this. The reason I mention this is that sometimes this condition is wrongly diagnosed based on tests that do not directly measure the acid. That could set you on the wrong track to get rid of your symptoms. There are several ways gastroenterologists treat low stomach acid. This depends on the cause of the condition. A gastroenterologist is best suited to diagnose and treat low stomach acid to prevent malabsorption of nutrients that can result from this condition. If there’s an H pylori infection, they treat that. If the person has been given acid blocking meds, they’re stopped. Sometimes, acid pills can be used. Other folks may need other therapies.

      It sounds like your problem is an early sensation of fullness leading to low food intake. A big cause of this is delayed emptying of the stomach, or gastroparesis. Those who eat a whole food, plant based diet with tons of healthy fiber, can get this problem because it takes much longer to move fibrous foods (especially raw cruciferous vegetables) through the system. I wonder if that’s the issue for you rather than low stomach acid or an iodine deficiency.

      There is a long list of potential causes for your symptoms, again best evaluated by a gastroenterologist. They can check how long it takes for your stomach to empty, for food to move through your intestines, for stomach acid as above, for problems in your esophagus. Now if you have sat down an talked with a GI doctor about any tests they’ve obtained, and they haven’t written down for you the possible causes of your symptoms, the tests they’ve done, what those tests ruled out or confirmed, and what treatment options there are for what they have confirmed, I’d suggest meeting with them again for this, or seeing a different GI who can communicate those things to you. (Sometimes, no cause may be identified for symptoms like yours. This can be enormously frustrating, and it’s hard to know how to reverse symptoms then.)

      If you’re found with delayed stomach emptying by a GI doctor, this is the one situation where reducing the fiber in your diet can be a necessary and good thing.

      Here is some patient information on your symptoms that could be of use as you wait to get in with a GI doctor. Best luck to you!

      Dr Anderson, Health Support Volunteer


  96. Well, my thinking is a little different than what you’ll find in these other posts. I have been studying the iodine issue in depth, as you can see from my posting above. First, the skin test for iodine seems to be valid for at least determining if you should be concerned. I have used it on about 10 people and the two that showed no deficiency truly were not deficient. It’s really simple .. take tincture of iodine (cheap at $3 a bottle in your grocery store or pharmacy) and cover a 3″ square with it. See if it disappears in less than 12 hours. If it does (mine went away in 5 hours and I was terribly iodine deficient) then test again in a different spot for a couple more days. It’s best to test on a fatty spot, like the upper thigh for instance or upper shoulder area. If it continues to show deficiency just buy real oral iodine and take it. The best out there is called iodoral, which has 6.5 mg or iodine and 6 mg of iodide. Iodide absorbs better in the thyroid so it’s good to have this 1-2 punch.

    Now, ask yourself why you are deficient. The reasons for lacking iodine are many but the key for true deficiency revolves around all of the hallides in our environment like fluoride, bromides, etc. Bromides used in baking and fire retardants in furniture, clothing, etc is a huge deal. All of these have the ability to be seen as iodine by your cell receptors but they do not work like iodine. They clog the receptors so that you do not get iodine absorption. When you become truly deficient your body is depleted of iodine stores. Your thyroid alone normally contains 23 mg of iodine, and it’s said that 20% of all of your iodine is stored in your skin, and then you have stores in many organs. Long story short .. if you are deficient it will take a LONG time to restore those levels in your body.

    While you might be concerned with 12.5 mg of iodine/iodide understand that when the medical establishment tries to test you for iodine they give you a one time dose of 50 mg, and that test doesn’t work well either, and surprise! .. it’s expensive. The problem is that your body cannot take up the iodine because the cell receptors are clogged with these haliides.

    So you need a two step approach. First you need to salt load, meaning something like a teaspoon of Himalayan salt mixed in 8 ounces of water and drink it. What will this do? It will bond to those halides and then your kidneys will flush them out. Start taking your iodine the same day. I thought that I would only have to salt load a few times but I have been at this for many weeks now and I am realizing that the process is going to take much longer. Some estimate that it might take up to two years to completely fix this deficiency.

    The good news is that if you truly are deficient you will feel like Superman/woman on the first day. No more brain fog, boundless energy like you haven’t had in ages, good sleep, and over the next few weeks your skin and hair will get much better too. BTW, I had a thyroid test too before all of this and I was “normal”. My test was a cascade test which tests the TSH and then goes on to test T3 and T4 only if your TSH is out of whack. Mine wasn’t so I only got my TSH levels. I cannot believe how out of touch the medical community is on this issue. If iodine was a prescription (Heaven forbid!) drug I imagine that the medical community would know all about it.

    BTW, a tell tail sign for halide overload/poisoning is cherry angeomas on your skin, and red dots on your skin. There are other signs too but this really hit home with me. I have had those for a long time and my doc only said not to worry about them.

    Best of luck!

  97. I contacted Maine Coast Sea Vegetables concerning the amount of iodine in their dulse flakes and thought that their reply might be of interest to some of you.

    “The dulse flakes have approximately 490 mcg in one teaspoon, so a tablespoon would be around 1470 mcg. The number is not exact and information is a “snapshot” of the nutritional values.”

    1. That is not right according to the label and what they say in their site.

      In the label of the dulse flakes from Maine Coast Sea Vegetables they say a tablespoon is 3g and has 330% of DV.

      DV is 150mcg.

      A teaspoon would be about 1g so 110% DV. So 1 teaspoon is about 150mcg not 490mcg.

      They also say this on their site. “In comparison, dulse contains about 150 mcg per gram. These amounts are approximations as there is variation depending on season of harvest and the age of plant.”

      So who is right?

      And yes I understand there is variation but 490mcg per gram is too much for dulse. Assuming 1 teaspoon is about 1 gram of dulse flakes.

      Correct me if I am wrong.

  98. Is a low sodium reading the same as low iodine? Will iodine supplementation help with raising my sodium reading? The more research i do the more confusing it is all getting. So table salt has iodine but i was told i have low sodium not low iodine. I have hashimoto’s. Been on a Whole Foods sos free diet for over 25 years. It was during that time i got the Hashimoto’s and also repeat uterine cancer( nearly 8 years survivor). If it was all as simple as adding iodine from kelp more frequently i would do it in a heartbeat. Can anyone explain the difference here?

  99. Hi, Dale! Although many people get their iodine from iodized salt, salt is sodium chloride, and iodine is added to make iodized salt. Low iodine and low sodium are not the same thing. I am not sure who is telling you that your sodium readings are low, as that is unusual. Hashimoto’s is an autoimmune condition, and too much salt often aggravates autoimmune conditions. Hashimoto’s is not caused by iodine deficiency, but iodine deficiency can exacerbate the condition. Many autoimmune conditions are improved with whole food, plant-based diets. In fact, one of my clients reversed her Hashimoto’s that way. Hashimoto’s sometimes coexists with celiac disease, in which case gluten elimination is crucial. For more on autoimmune conditions, you may want to see these resources, if you have not already. https://nutritionfacts.org/topics/autoimmune-diseases/
    By the way, Dr. Greger does not recommend kelp or kombu for iodine, as it can provide too much. The other types of sea vegetables featured in the video are better choices.
    I hope that helps!

  100. I highly value Dr Gregor and his philosophy. My dad had hypertension and probably was saved by the recommendations made here on the website.

    However regarding iodine I am not sure if I can share all the views suggested here.

    If a little higher dose of iodine is so bad why do the Japanese live so long? Asians eat tons of kelp – according to the Western RDA system many would have overdoses of 1000% and more on daily basis! Why does it benefit them rather than do harm?

    Why there are supplements with several mg iodine content on Amazon that have thousands of reviews and excellent ratings? These are Western buyers!

    If people want to optimize their situation they should look into this

    1. Excellent Question Phil, why doesn’t Kelp harm Asians, we probably know this this for sure, don’t we? I am at a loss to understand why a tiny bit of whole Kelp powder is considered potentially harmful by Dr. Greger. Please explain.

      —–Original-Nachricht—– Betreff: Phil commented on Avoiding Iodine Deficiency

    2. Here’s some well researched insight into how much iodine the Japanese are likely eating:

      It offers some interesting details on types of seaweed sources, variations of iodine content due to area harvested and preparation method. For example:
      “When kombu is boiled in water for 15 minutes it can lose up to 99% of its iodine content” It is my understanding that in the making of dashi broth the kombu is removed and not actually included in the soup but just used to flavor the broth.

      The article also notes a dramatic decrease in the consumption of certain high iodine types of seaweed since the 1960’s with a possible increase in consumption of lower iodine sources such as Nori and Wakame.

  101. My 23 year old daughter appears to have Hashimoto’s. Is there any hope/research that show that a thyroid can recover or be restored to health? She has been eating plant-based for a couple of years now.

    1. Hello Tim,

      As of right now I’m not aware of any research showing reversal of Hashimotos by adopting a plant-based diet; however, Hashimoto’s is an autoimmune condition and there is some exciting research, as well as anecdotes, out there demonstrating that plant-based diets can really benefit those with autoimmune disease. And a bonus is that the side effects are all good side effects, so it may be worth a try.

      I hope this is useful,

      Matt, Health Support

      1. Thank you for your input. I was plant based for 14 years when I learned I had hashimotos. Still am. I do feel that one can keep inflammation low and reduce antibodies activity on plant based. But, I also see the importance of a very low fat diet. Dale

  102. I don’t think that Dr Gregor has had the time to get into the complexities of iodine deficiency. It’s often driven by exposure to bromides which clog the iodine/iodide receptors to produce a deficiency. Here is great place to gain an understanding of what is likely driving the issue ..

  103. I’m confused by the math. 2 ounce package of Dulse is a month supply for an adult?
    I’m looking at a package of organic whole dulse, and the serving size is 1/4 cup (55 grams) and it says the % Daily Value for Iodine for that serving size is just 2% ??

    Seriously, lists 10g protein (20%), 17mg IRON (90%), Vitamin B12 (140%), but Iodine 2%

    So 1/4 cup of dulse rated as just 2% of my daily requirement is what? Wrong? “Origin: Bay of Fundy, New Brunswick, Canada”
    I’ve just emailed the company to ask if 2% is a typo … perhaps it should read 20% but I shouldn’t assume the label is wrong. It doesn’t state the mcg just the %. But at 2% of recommended daily value, I’d have to eat 24 x 4 oz bags of the stuff to achieve 100%. This makes no sense at all.

  104. I was drawn to this site due to scientific based, unbiased factual information. Your disclosing the contributors to each study, and warning against those studies that are colored by corporate greed, had been also attractive.

    Now I feel I am under information overload. I find myself hoping for summary information. On this subject, for example: a list of seaweed available, and their pythonnutrtiens (like iodine) n pythtoxin(like arsenic) content might help, with daily recommended and max amts. So, I can know which seaweeds, sea algea products are healthy choices in what amts. It would also be helpful to know Dangerous/poisonous ones to avoid. Like your video mentioned “hiziki”. I wish you had a black food category for all food groups. Like can we nave a refence list for all food items that had been shown by science to be dangerous, and luckily had been gotten on national, and/o international health agencies shit list for all food groups.

    How could we find unbiased info some other seaweed/algee products not addressed by you yet? One that I came across is spiriluna. Google search mentions how some brands were found to contain toxic levels of heavy metals, including arsenic. https://healthyeating.sfgate.com/dangers-spirulina-7035.html. How do we make sure what we get is not one of those brands. How could we the consumers protect ourselves from unregulated food industry greed? Avoiding all processes food would be the first step, Yet Would not “collecting, packaging, and. distributing food items we can otherwise not get” still be processing. Scanning ingredients is one step, yet those ingredients contain chemical product names, and we ordinary people like myself have no idea what kind of compound listed chemical is referring to, and whether it is something we should avoid.

    I dream of an app. Taken the photos of each food product will tell us what color category that product belongs.

  105. I bought a 1.76 oz package of wakami…their serving is 3TBLS…but says anything about iodine …how much of this crap should i eat to get my 53 year old male body working properly…

    1. I know, for some strange reason the iodine content is sometimes not listed but if it’s wakami then a tablespoon a day is plenty. Once you’ve done that for a week you could go alternate days.  You should get sufficient iodine.  Especially if you eat any other seaweed or sea veggies.

  106. Hello, Dr. Greger !

    Thank you for the great video.

    I was discussing the information with my teacher and she told me an interesting case about a friend of hers, who is consuming hiziki because as she is claiming :
    “Hiziki contains natural arsenic(it is plenty present in nature) and also will have that cleansing effect in ocean water.

    The special quality of seaweed in general is that it takes out heavy metals from our body.

    Eating hiziki is ok.
    For the past decades (since I started macrobiotics 45 years ago) there had been a ban on kombu, on nori on hiziki for these reasons

    We continue to eat it.
    When we have blood test done, the blood never had shown elevated levels of heavy metals.

    The researchers analyze the product but don’t know the effect on the body after we have cooked it and eaten it.
    We use it twice a week and no one has elevated arsenic levels!”

    Personally, I do not consume it, and I do not intend to, but I thought that her experience was, at least, interesting.

  107. Dear Dr. Gregor, I’ve eaten about 10 sheets of Nico-Nico Nori per day for the last year. It’s a product of China, and I just noticed a black box warning: “Consuming this product can expose you to chemicals including lead, inorganic arsenic, and cadmium, which are known in the state of California to cause cancer…” . Is 10 sheets per day too many for any brand no matter where it’s harvested, should I just find a different source, or is it really a small risk of harm? Also, where can we post questions for the monthly Q&A? Thank you! Kate

    1. Hi, Kati! The level of contamination of sea vegetables depends greatly on the source. I would look for ones from the North Atlantic. That said, 10 sheets a day of nori is a lot. It might be wise to cut back on that. Two sheets a day should be all you need. More on that here: https://nutritionfacts.org/video/too-much-iodine-can-be-as-bad-as-too-little/
      You should be able to sign in and post your questions for the Live Q&As in the comments sections of YouTube or Facebook. More on those here: https://nutritionfacts.org/live/
      I hope that helps!

  108. Hello, I’m curious if you know of any new research relating to B12 analogues contained in dulce/seawead and how they may interfere with the absorption of b12? Vegans and plant based eaters are encouraged to get iodine from sea vegetables like Dulce, but I wonder if by meeting our nutritional requirements for iodine we may fail to get the B12 we need. Might potassium iodide be a better option for vegans? Thank you.

    1. You can take your B12 supplement first thing in the a.m. and not worry about foods that might hamper absorption.  You can also get B12 from duckweed, the only plant source recently discovered.  If you’re 60 & over, be aware of the huge recommended daily intake of B12 compared to the recent deductions in daily dose recommendations for younger folk.

      1. So, B12 analogues in food like dulce will not cause issues with the absorption of true B12 as long as the B12 supplement is taken in the morning, but if the B12 supplement is taken with or after foods containing a B12 analogue, the body may confuse the B12 analogue for true B12? Do I understand that correctly?

    2. Hi, Les! The greatest danger, as I see it, with regard to dulse and other sea vegetables is that they can make blood levels of B12 seem high even if a person is dangerously deficient in B12. More on that here: https://nutritionfacts.org/questions/are-there-known-risks-of-excess-b12-consumption/ That doesn’t mean that people should avoid sea vegetables. Just don’t eat them at the same time you take your B12 supplement. You can find everything on this site related to vitamin B12 here: https://nutritionfacts.org/topics/vitamin-b12/ I hope that helps!

  109. Dear Everybody,
    Hello, I’m from Hungary. We are vegans for more than 20 years. Most of our family have hypothyreosis. We got Mr. Greger’s book “How to not die?” two months ago. We red here that the daily iodine dosage is 150 micrograms. We have another book: “Lynna Farrow: THE IODINE CRISIS-What You Don’t Know About Iodine Can Wreck Your Life”. There is a lot of projects inside, which proves that it’s necessary much more iodine for the body. In the book, you can read that mankind use iodine from the beginning of our history for healing with a very good result. But in the middle of the 20th century, there were two doctors Wolff and Chaikoff who published their theory, what they’ve got after their tests on rats, that maybe not necessary so much iodine. From that period iodine usage was drastically restricted. Only at the beginning of the 21st century, Dr. Guy E. Abraham started to research the lack of iodine. Do you read this book? What is your opinion about this book and about the content? And then what is the necessary iodine amount? My email address: mentes.vilmos@gmail.com

    1. I would believe the book on iodine deficiencies, Mentesvili. There seems to be much more going with iodine that “modern” science has not yet addressed or figured out. I believe that some of it might be genetic because everyone that I’ve skin tested in my immediate family, even though we’ve lived in different environments for decades, has the same issue with iodine. I have also tested a lot of people that had no deficiency. If you look above you’ll see multiple postings I’ve made on this thread. Read them if you like. BTW, when I tested deficient I had been taking 1 mg per day of sea iodine, made by LEF, for over a DECADE. I am now taking 56 mg of potassium iodide in the form of Iodoral. I hope to someday be normal but I’ve been on this high dose for over 6 months after spending over a year at the 12.5 mg dose.

      1. Hi John. I have read David Browstein’s book on Iodine and he says that skin iodine tests are very unreliable to check for a deficiency. However he does recommend everyone take much more iodine than is recommended (i.e. 12.5 mg rather than 150 mcg). Apparently bromine toxicity (found in fire proof beds, pesticides, car interiors, bread) block iodine from functioning as effectively as needed, but obviously not to the point of giving people Goiters. I take at least 5mg / day based on what I’ve read.

        1. I agree with your premise Jackson. Conventional iodine testing involves a 50 mg dose and then monitoring urinary excretion for 24 hrs. If uptake is 90% or so you are classed as non deficient. However, if your receptors are blocked by bromides, etc you won’t uptake very much. I believe that the skin test is more accurate in these cases. All human cells need iodine and iodine is absorbed thru the skin so determining the time of absorption from the skin is effective because if the skin is deficient it will absorb faster.

          After my experiences with iodine I would say that the 12 to 15 hour measure for skin absorption using any type of liquid iodine is a good measure. Tincture or iodine is cheap and easy to find but you get similar results with providone iodine, which is used by the medical establishment extensively and is also dirt cheap. Dosing to eliminate the 2-3 pm drag is also a worthy sign that you need more.

  110. Dear Mr. Greger,

    Thank you very much for your work, researches what you’ve done. It is very important and useful for everybody.

    This topic of iodine is also very important. I assume and hope, that you’ve read all the books in connection with this topic. Probably you could read the above-mentioned book (“Lynna Farrow: THE IODINE CRISIS-What You Don’t Know About Iodine Can Wreck Your Life”). I couldn’t find any reference to this book and its content. Why? If it’s true that we need much more iodine intake, we have to take milligrams of iodine instead of micrograms. But, if it’s not true, but false, necessary to point out what is the problem with it, why is it not true! There is a big difference between 150 micrograms and min.50 milligrams/day. That’s why it is important how much I take in. Could you advise us? Thank you in advance!

    1. Mentesili

      Trying a higher dose of iodine contains no real risks. Chronic use of iodine in doses above your body’s desired amount IS serious, and is to be avoided.

      Have you ever had a CT scan .. a chest CT scan, perhaps. In that you are routinely subjected to 300 plus mg of iodine. Most people do not have a reaction to that, BTW. I, on the other hand had a strange reaction to it, according to the staff. I was given a pre treat drink which immediately nearly put me to sleep. Then upon entry to the machine was given an IV dose which perked me right up. Very strange according to the staff. I bring this up because it shows that trying a higher than recommended dose of iodine will not damage you, and that my reaction to it is likely the kind of thing you experience when you have iodine issues.

      I would purchase some iodoral (the best form I’ve found), in the 12.5 mg size. Take one and see if you feel improvements. I would also personally recommend skin tests to see how much you need. See my above posts for that info.

      Best of luck!

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