Do Vitamin D Supplements Reduce the Risk of Dying from Cancer?

Do Vitamin D Supplements Reduce the Risk of Dying from Cancer?
4.64 (92.8%) 25 votes

Sun exposure is associated with lower rates of 15 different cancers and improved cancer survival. What happened when vitamin D supplements were put to the test?

Discuss
Republish

Below is an approximation of this video’s audio content. To see any graphs, charts, graphics, images, and quotes to which Dr. Greger may be referring, watch the above video.

It all started with this famous study, published in 1980. Johns Hopkins researchers were trying to figure out why states like New Mexico and Arizona have only about half the colon cancer rates of states like New York, New Hampshire, and Vermont. Maybe it’s because they got so much sun. And so, they proposed that maybe the sunshine vitamin—vitamin D—is a protective factor against colon cancer. Since then, sun exposure has been associated with lower rates of 14 other types of cancer, too.

Vitamin D may also affect cancer survival. Higher blood levels of vitamin D were associated with lower mortality of patients with colorectal cancer. How much lower? Like nearly half the mortality. And, the higher the D levels, the lower the death rate appeared to fall. This may explain why the survival rate from colon cancer may depend, on part, on the season of diagnosis—the reason the risk of a rapid death is lowest if you’re diagnosed in the fall, after you’ve spent the summer building up your vitamin D stores.

But look; there are other risk factors that could be seasonal, too. Maybe people are taking advantage of the fall harvest, and eating healthier. Maybe that’s why the lower risk in the fall season. Or, maybe there’s more drinking in the winter. And, in the summer, running around outside, not only are you getting more sun; you’re running around outside, getting more exercise—which may itself be protective.

So, these kinds of studies just provide circumstantial evidence. Establishing a cause-and-effect relationship between colon cancer and vitamin D deficiency using observational studies is challenging, because of confounding factors like the exercise—so-called “lurking variables.” For example, there may be a tight correlation between ice cream sales and drowning deaths, but that doesn’t mean ice cream causes drowning. A more likely explanation is that there is a lurking third variable—like hot weather, summertime—that explains why drowning deaths are highest when ice cream consumption is highest.

That’s kind of a trivial example. But, this actually happened with hormone replacement therapy. Women taking drugs like Premarin appeared to have 50% less risk of heart disease. And so, doctors prescribed it to women by the millions. But, if you dig a little deeper into the data, yes, women taking estrogen had 50% lower risk of dying from heart disease. But, they also had a 50% lower risk of dying from accidents and homicide. So, it probably wasn’t the drug. See, the only way to know for sure is to put it to the test, in a randomized clinical trial, where you give half the women the drug, and see what happens.

And, a decade later, they did. And, instead of having a 50% drop in risk, within a year of being given the hormone pills, heart attack and death rates shot up 50%. In retrospect, the lurking variable was likely socioeconomic class. Poor women are less likely to be prescribed hormone replacement therapy, and more likely to be murdered, and die of heart disease. Because of the lurking variable, a drug we now know to be dangerous had appeared protective.

Besides lurking variables, there’s also the possibility of reverse causation. Maybe low vitamin D levels didn’t worsen the cancer. Maybe the cancer worsened the vitamin D levels. This may be unlikely, since tumors don’t appear to directly affect vitamin D levels. But cancer treatment might. Even simple knee surgery can dramatically drop vitamin D levels within hours, thought to be because of just the inflammatory insult of cutting into somebody. So, maybe that could help explain the link between lower D, and lower survival. And hey, if you’ve got cancer, maybe you’re spending less time running around at the beach.

So, yes, higher vitamin D levels are associated with improved survival in colorectal cancer, and in breast cancer. In fact, about double the risk of breast cancer recurrence and death in women with the lowest vitamin D levels. And, vitamin D levels also associated with longer survival with ovarian cancer, and other cancers, like lymphoma. But, bottom-line, as we learned with hormone replacement, is that you have to put it to the test. But, there weren’t a lot of randomized controlled trials on vitamin D supplements and cancer—until now.

We now have a few randomized controlled trials, and vitamin D supplements do indeed appear to reduce the risk of dying from cancer. What dose? The researchers suggest maybe getting blood levels up to at least around 75 nanomoles per liter; levels not reached by as many as three-quarters of women with breast cancer, or a striking 97% of colon cancer patients.

Getting up to these kinds of levels, 75, or perhaps even better, 100, might require about 2,000 to 4,000 international units of vitamin D a day—levels of intake for which there appear to be no credible evidence of harm. Regardless of what the exact level is, the findings of these kinds of studies may have a profound influence on future cancer treatment.

Please consider volunteering to help out on the site.

Images thanks to mahnoorraja via flickr and ClkerFreeVectorImages and ClkerFreeVectorImages via pixabay.

Below is an approximation of this video’s audio content. To see any graphs, charts, graphics, images, and quotes to which Dr. Greger may be referring, watch the above video.

It all started with this famous study, published in 1980. Johns Hopkins researchers were trying to figure out why states like New Mexico and Arizona have only about half the colon cancer rates of states like New York, New Hampshire, and Vermont. Maybe it’s because they got so much sun. And so, they proposed that maybe the sunshine vitamin—vitamin D—is a protective factor against colon cancer. Since then, sun exposure has been associated with lower rates of 14 other types of cancer, too.

Vitamin D may also affect cancer survival. Higher blood levels of vitamin D were associated with lower mortality of patients with colorectal cancer. How much lower? Like nearly half the mortality. And, the higher the D levels, the lower the death rate appeared to fall. This may explain why the survival rate from colon cancer may depend, on part, on the season of diagnosis—the reason the risk of a rapid death is lowest if you’re diagnosed in the fall, after you’ve spent the summer building up your vitamin D stores.

But look; there are other risk factors that could be seasonal, too. Maybe people are taking advantage of the fall harvest, and eating healthier. Maybe that’s why the lower risk in the fall season. Or, maybe there’s more drinking in the winter. And, in the summer, running around outside, not only are you getting more sun; you’re running around outside, getting more exercise—which may itself be protective.

So, these kinds of studies just provide circumstantial evidence. Establishing a cause-and-effect relationship between colon cancer and vitamin D deficiency using observational studies is challenging, because of confounding factors like the exercise—so-called “lurking variables.” For example, there may be a tight correlation between ice cream sales and drowning deaths, but that doesn’t mean ice cream causes drowning. A more likely explanation is that there is a lurking third variable—like hot weather, summertime—that explains why drowning deaths are highest when ice cream consumption is highest.

That’s kind of a trivial example. But, this actually happened with hormone replacement therapy. Women taking drugs like Premarin appeared to have 50% less risk of heart disease. And so, doctors prescribed it to women by the millions. But, if you dig a little deeper into the data, yes, women taking estrogen had 50% lower risk of dying from heart disease. But, they also had a 50% lower risk of dying from accidents and homicide. So, it probably wasn’t the drug. See, the only way to know for sure is to put it to the test, in a randomized clinical trial, where you give half the women the drug, and see what happens.

And, a decade later, they did. And, instead of having a 50% drop in risk, within a year of being given the hormone pills, heart attack and death rates shot up 50%. In retrospect, the lurking variable was likely socioeconomic class. Poor women are less likely to be prescribed hormone replacement therapy, and more likely to be murdered, and die of heart disease. Because of the lurking variable, a drug we now know to be dangerous had appeared protective.

Besides lurking variables, there’s also the possibility of reverse causation. Maybe low vitamin D levels didn’t worsen the cancer. Maybe the cancer worsened the vitamin D levels. This may be unlikely, since tumors don’t appear to directly affect vitamin D levels. But cancer treatment might. Even simple knee surgery can dramatically drop vitamin D levels within hours, thought to be because of just the inflammatory insult of cutting into somebody. So, maybe that could help explain the link between lower D, and lower survival. And hey, if you’ve got cancer, maybe you’re spending less time running around at the beach.

So, yes, higher vitamin D levels are associated with improved survival in colorectal cancer, and in breast cancer. In fact, about double the risk of breast cancer recurrence and death in women with the lowest vitamin D levels. And, vitamin D levels also associated with longer survival with ovarian cancer, and other cancers, like lymphoma. But, bottom-line, as we learned with hormone replacement, is that you have to put it to the test. But, there weren’t a lot of randomized controlled trials on vitamin D supplements and cancer—until now.

We now have a few randomized controlled trials, and vitamin D supplements do indeed appear to reduce the risk of dying from cancer. What dose? The researchers suggest maybe getting blood levels up to at least around 75 nanomoles per liter; levels not reached by as many as three-quarters of women with breast cancer, or a striking 97% of colon cancer patients.

Getting up to these kinds of levels, 75, or perhaps even better, 100, might require about 2,000 to 4,000 international units of vitamin D a day—levels of intake for which there appear to be no credible evidence of harm. Regardless of what the exact level is, the findings of these kinds of studies may have a profound influence on future cancer treatment.

Please consider volunteering to help out on the site.

Images thanks to mahnoorraja via flickr and ClkerFreeVectorImages and ClkerFreeVectorImages via pixabay.

Doctor's Note

What about just getting sun instead? Be sure to check out my six-part video series:

It’s better, of course, to prevent colon cancer in the first place. See, for example:

For more on that extraordinary story about Premarin and hormone replacement therapy, see How Did Doctors Not Know About the Risks of Hormone Therapy?.

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

172 responses to “Do Vitamin D Supplements Reduce the Risk of Dying from Cancer?

Comment Etiquette

On NutritionFacts.org, you'll find a vibrant community of nutrition enthusiasts, health professionals, and many knowledgeable users seeking to discover the healthiest diet to eat for themselves and their families. As always, our goal is to foster conversations that are insightful, engaging, and most of all, helpful – from the nutrition beginners to the experts in our community.

To do this we need your help, so here are some basic guidelines to get you started.

The Short List

To help maintain and foster a welcoming atmosphere in our comments, please refrain from rude comments, name-calling, and responding to posts that break the rules (see our full Community Guidelines for more details). We will remove any posts in violation of our rules when we see it, which will, unfortunately, include any nicer comments that may have been made in response.

Be respectful and help out our staff and volunteer health supporters by actively not replying to comments that are breaking the rules. Instead, please flag or report them by submitting a ticket to our help desk. NutritionFacts.org is made up of an incredible staff and many dedicated volunteers that work hard to ensure that the comments section runs smoothly and we spend a great deal of time reading comments from our community members.

Have a correction or suggestion for video or blog? Please contact us to let us know. Submitting a correction this way will result in a quicker fix than commenting on a thread with a suggestion or correction.

View the Full Community Guidelines

  1. Wow….I was expecting a big, fat NO, as I know the Doc is not a big supplement guy. What I need clarification on, however, is whether we should all be taking Vit D. as a preventative, or if this study application is limited to surviving cancer, but not necessarily preventing it.

  2. Been taking 10000iu a day of Vitamin D3 for little over 10 years. I was ridiculed and laughed back then when I told my doctor, friends and family how much I was taking and advised them to take at least 4000/5000iu day together with a capsule of Vitamin K complex. They all advised me to stop as I could die been a Vitamin D a Hormone and been the daily max amount suggested by the government only 200iu at that time. I am still alive and well and still taking 10000iu daily. Thank you Dr. Greger again for your marvelous job in letting people know the truth.

    1. Good for you. But the reality for me was that I was very sensitive to vit. D and any supplementation above the level of 27 ng/mL (careful with units, ng/mL not nmol/L), which is still borderline insufficiency, caused me hypercalcemia. I had no problems with parathyroid though but I had hypercalcemia – which was very very strange.

      So you have to be careful with high dosage, less so with lower dosage.

      1. Yeah Mick I started with 4000iu and did the blood tests after 6 months of supplementation and increased the dose by 1000iu gradually every 3-4 months or so until arriving at 14000iu/daily which put my serum level at around 60ng/ml (150 nmol/L) which based on my own researches was putting me inside the ideal wanted range. It is extremely important though to supplement with a good K complex. The vitamin D transport the calcium to where it is needed but only the vitamin K utilize it and fix it to where it’s supposed to go. Not enough vitamin K in your body and you will end up with hypercalcemia. I take a K complex and I also eat a lot of Japanese Natto (nearly 70-100 gr every 2 days) as my wife she is japanese so I ingest K vitamin also in that way. I am lucky as my wife she is a doctor and her father also has a clinic so I can take any blood test I want anytime and they have been following me. Never experienced Hypercalcemia but I bet if I cut on K and natto things could be different. Sorry about my poor English.

          1. Hi Nancy. I take a capsule of K Complex of 2700mcg whenever I take Vitamin D3 supplement. This complex is composed by: Vitamin K1 1500mcg, Vitamin K2(menaquinone-4) 1000mcg, Vitamin K2(menaquinone-7) 200mcg. This is enough by itself to keep me away from Hypercalcemia. Also using Natto 1-2 days/week. The brand I am using is LifeExtension Super K complex but only because I fund it cheap where I live. Before I was using a different brand and same results so I guess any K complex may do the job.

            1. Dear LT Nimitz,

              My apologies for the long delay. Thank you so much for most informative reply! It is most appreciated!

              But… I just self-tested myself (self muscle testing) and as much as I DO BELIEVE in taking high doses of Vitamin D3, my body kept telling me otherwise?

              Hmmmm…. wonder why?

              Thanks again, LT Nimitz

              1. Hi Nancy I guess you cannot go wrong following what your body is telling you and if your level after a test it is good why supplement? You can always go in the sun during day time and get it that way I guess. Here there is a very good site about vitamin D3. Sorry for my english but it is not my first language as you probably assumed.

                http://grassrootshealth.net

          1. I mix it with a little soy sauce (just few drops), radish and a Japanese sauce made of vegetables that my wife buy all the time for soba noodles. I mix it and use it on black rice and lentils cooked with the rice cooker or just on top of crunchy Italian bred. i could not stand it at the beginning but after I became accustomed to it and now I simply love it.

          2. What I do I mix it with few drops of soy sauce and I add Turmetic powder, ground black pepper and 2 chopped walnuts. Mix well and put it on top of a Wholemeal bred toasted. Taste really like cheese. Combined with the crunchy bread is heaven.

      2. When I take more than 1,500 IU of vitamin D per day I get a few minor heart palpitations. I’m wondering if the vitamin D is messing with my calcium/magnesium balance. I get enough calcium and magnesium in my diet (and also take vitamin K2). Vitamin D from sun exposure does not cause any problems (except ruining my skin).

        1. Hi Julie, I noticed if I take my vitamin D3 at night before bed or after dinner will take me longer to fall sleep so I take it after lunch or after breakfast. I also used to have some minor heart palpitations few years back but I am sure was for lack of Potassium and magnesium. All was fixed when I moved to a complete plant based diet mostly comprising of green vegetables, grains and legumes plus once or twice a week I make a dates water with my blender and add some magnesium and potassium gluconate and never had this issue any longer. So may be because low level of these two important minerals in your body from your diet and not because the vitamin D causing it as I am fine now. Try to eat more foods that contains them and you could add (if you really want but it is not essential) some powdered supplements as a gluconate form.

        2. I will also have heart palpitations from vit. D, but only if I take the pill on empty stomach. No side effects if taken with a meal.
          It’s kind of major inconviniece for me, as an intermittent fasting devotee I have regular fasting days, so no vit. D pills on those days for me pity.

          1. Thanks for that, Uni Verse. I will try taking vitamin D with a meal. I do IF as well, but only for ~17 hours so that shouldn’t be a problem.

          2. I realize this is a month later: but were you aware that Vitamin D lasts a long time in your system (to get you through the dark winter months), so you don’t need to take it every day? You could easily take a week’s worth of vitamin D intake on a non-fasting day, and then not have to worry about not being able to take your daily dose on a fasting day. Ever since I was diagnosed with low vit d (only 6 nmol/L!) I have been taking 20,000 IU per week, it’s easy enough to make it a Sunday morning tradition with a hearty breakfast to avoid any trouble.

            1. Thanks for your input. How long have you been taking 20k pills?
              Personally, as a first-time user of vit. D, I’m a bit wary of high dosage. Before pills, my starting vit. D read 18ng/ml. So it was better to play safe, as I’ve seen in other’s experiences even 2k dosage broke their vit. D status through the roof. So D saturation efficiency must vary wildly in different people.
              Maybe after 3 month, I can go and check my blood works, and then play accordingly.

    2. I’m taking 7000 IU/day and tested at 60 ng/ml. Also take vit K. Have heard recommendations that people keep calcium supplements under 500 mg / day.

      1. I personally do not supplement with calcium just eating copious amounts of greens, oats and legumes. My blood test shows it is perfectly fine.

  3. I’m glad to see this video, and particularly pleased to note that Dr. G makes the case for using the blood level rather than the dosage level as the important thing. However, he uses nmol/l as a unit. A lot of what you may read about vitamin D uses ng/ml, and the two are very different. You can use http://www.vitamindservice.com/node/91 to do the conversion. The level of 75 nmol/l that Dr. G mentions converts to just 30 ng/ml. When I had my D level tested in January, it was 17. The lab report had 30-100 ng/ml as the reference range. There are some, such as Dr. McDougall, who think the low end of that range is too high, but I disagree, and I think Dr. G disagrees as well.

    I think a case can be made that even 30 is too low. Prior to civilization, human beings spent a lot of time outdoors in sunny parts of the world. Compared to other primates our bodies are virtually hairless. Skin pigmentation varies but in general lighter skin is more efficient at making D in sunlight. All of these factors together are adaptations for maintaining D levels. So how high is normal? Maybe the best way to answer that is to look at the levels of people today who spend a lot of time outdoors with a good amount of skin uncovered. Their D levels are in the 50s, in ng/ml. To get to that level using supplements, you might have to take 5,000 or so IU, but it depends on your age, weight, and skin color, as well as your typical sun exposure. People with dark skin need more, because the melanin downregulates D production. People with really fair skin will need less.

    There’s an app you can get on your iPhone or Android phone called “dminder” that helps you to estimate your D level. I started using it last winter before I got lab results. The value it estimated was 18, very close to my actual lab value of 17. Since then I’ve supplemented and as of today dminder estimates my level at 57 ng/ml. I’ll be getting another lab test soon (There are home tests too).

    https://www.youtube.com/watch?v=QrU1yrmNIqc presents some important work on D and prostate cancer. This is direct interventional research, not just observational research.

    1. Thank you, Todd, for pointing out about the different units used for measuring Vit D levels. I think you have a typo error in your first paragraph, above, where you say Dr. McDougal thinks “the LOW end of that range is too high”. Don’t you mean “the HIGH end of that range is too high”?

      1. @DrJon_NF_Vol:disqus No, I mean the low end, as written. As I recall, he has argued that we don’t need to be as high as 30 ng/ml. I believe he thinks 20 is adequate. Personally, I think the weight of the evidence is against him.

        It’s actually easy for me to produce 4,000 to 5,000 IU of D just doing yard work for an hour or so on a sunny summer day where I live (Philadelphia), with my shirt off. My skin type is medium. At the start of the summer I can burn if I’m not careful; after that I tan easily and get pretty dark. But since I don’t spend that kind of time in the sun every day, I supplement. As I recall, even frequent golfers, who spend a lot of time in the sun, are often below 30 ng/ml when tested, since most of their body is covered while they play. In short, it’s just not easy to get enough sun in the course of normal civilized life. People of African descent living in temperate or northern (or southern, in the southern hemisphere) latitudes should probably *all* be using substantial supplements, unless they are getting pre-formed D from cod liver oil or something of the sort.

        At the moment I’m taking 7,000 IU/day along with plant-sourced K2.

        1. Todd – your comments are very helpful, but I am curious about the Vitamin K. I take it Vit K must help the absorption of Vit D? I looked up food sources of Vit K in my (original version) copy of “Becoming Vegan” & according to it, Vitamin K is found in so many plant foods (leafy greens, cabbage, broccoli, asparagus, lentils, peas, pumpkin, sea veggies…) that a plant-based diet will have it in abundance. They give an example of 1/2 cup fo kale providing 179 mcg of Vit K, more than double the highest RDA (men age 25+: 80mcg). I interpreted your coment about taking “plant sourced K2” as meaning you’re taking it as a supplement rather than taking your Vit D with foods that include any of those I listed as good sources of Vit K. Is there something I’m missing?

          1. Laloofah Vitamin K has two variants, K1 and K2. For a long time, there were thought to do the same thing. K1 is mainly about blood clotting and, as you say, it’s plentiful in many plant foods. K2 is produced by bacteria in the gut from K1. K2’s role is only beginning to be understood since about 2009. One of the things that K2 does, that K1 doesn’t do, is direct calcium into bones and teeth, and out of soft tissues, such as arteries. See https://www.youtube.com/watch?v=jPWCJxyHAg4

            There is no simple blood test or other test for “K2 levels”, so there’s some guessing involved in whether anyone “needs” K2 supplements. We do know, however, that the “Factor X” discovered by Weston Price in the 1930s that helped to restore health to many people was K2. He found it in butter from pasture-fed cows, especially from cows fed rapidly growing green grass in the spring.

            For those who want to avoid butter or aged cheeses, the main plant source of K2 is natto, the fermented soybeans eaten in northern Japan, but not liked in southern Japan. This is believed to be the reason why the rate of hip fractures is much lower in northern Japan. If you buy K2 supplements, the “MK7” kind is from natto; the “MK4” kind is animal-sourced.

            What this has to do with vitamin D supplementation is this: D helps your body to absorb the calcium in the foods you eat, which is a good thing. So when you supplement, you’re getting more calcium from your food. But you want that calcium to go where it belongs, into bones and teeth and not into your arteries (arterial plaques are highly calcified, and coronary calcium score is a strong CVD risk factor). There are anecdotal reports that K2 supplementation can reduce cardiac calcium score, but I don’t think this is scientifically confirmed yet. There’s a lot of research going on in this area.

            So it’s really up to each of us to decide whether it’s safe to assume we’re making all the K2 we need from K1. I’m assuming that I’m probably not, and since I’m absorbing more calcium due to my D supplementation, it makes sense to me to take K2 as well.

          2. Laloofah: To add to Todd’s comments, there’re two types of vitamin K2: MK4 and MK7. MK4 occurs only in animal foods, but the human body can convert K1, which is abundant in plant foods, to MK4. MK7 occurs neither in plants nor in animals. It occurs only in fermented foods. So MK7 is the hardest to get.

            1. Thank you, George! I’m vegan so won’t be eating any animal-sourced foods, but I interesting about the fermented foods being a source for MK7. In fact, when Todd mentioned “natto” (with which I am not familiar, yet) I thought right away of tempeh, also made from fermented soybeans. More specifically, I thought of the tempeh in my freezer that I’d forgotten about since last using in August, so thank you both for the reminder! :-)

        2. Todd, how much (and what brand) K2 do you take? Could you please recommend a good source for determining dosage? I take 2500 IU of a vegan D3 daily but didn’t know that K2 was important, too. Thanks so much!

          1. Heidi did you see the link above on nutritional supplements that Dr. Greger recommends taking? He does not list K as necessary which makes me think there is no research to support the taking of Vit K. What are your thoughts on that?

            1. WFPBRunner: I’ll also add that in the book Becoming Vegan by Brenda Davis and Vesanto Melina, they thoroughly research and cover just about every vitamin I think. Here’s what I found from that book: On page 119 of the Express Edition, the book says: “If you follow popular health gurus on the Internet, you may wonder if you need supplemental vitamin K2, since little of this form is present in a vegan diet. At this time, there is no scientific evidence to suggest that vegans need to worry about supplementing with Vitamin K2.”
              .
              That’s a trustworthy source. They make note that leafy green veggies are vitamin K superstars. And it is easy to get enough Vitamin K on a whole plant food diet. That seems to be all we need to worry about. There is no (credible) scientific evidence, at least by 2013 that says otherwise.
              .
              On page 119 is the text, “…intestinal bacteria synthesize forms of this vitamin known collectively as vitamin K2…” I interpret that to mean: It looks like our bodies make K2, as least in those people who have healthy guts. Perhaps rather than worrying about consuming K2, people should strive for the goal of consuming gut health promoting foods such as intact grains.
              .
              I found backup for my understanding of K2 from an article written by another well respected expert, Jack Norris RD: “Menaquin one (K2) is produced by a number of different bacteria species that typically live in the digestive tract of humans, and can be absorbed in the distal part of the small intestine. Unless someone has had significant antibiotic therapy, they should have plenty of such bacteria providing them with menaquinone.” Anyone concerned about vitamin K in any form, may want to check out this article: http://www.veganhealth.org/articles/vitamink (Thank you Darchite for bringing this to my attention!)
              .
              For anyone that missed it, Tom Goff replied to George in another post with a page link on some more technical information about K2. (Thank you Tom!). If you want the more technical details, check out this interesting page: http://lpi.oregonstate.edu/mic/vitamins/vitamin-K.

              1. Thanks Thea; I do eat several servings of a variety of leafy greens every day, so I’ll stop worrying about K2. I recently bought the Brenda Davis book; looks like I’d better get busy reading it!

                1. :-) I’m sure people do read Becoming Vegan. I found it more to be a good reference book, looking up specific questions/nutrients, than something I wanted to read from front to back. Either way, it is a good book to have in the home library. Enjoy!

                2. Heidi:
                  There is no K2 in greens. Again, K2 is altogether different from K1 (for which greens are a terrific source).

                  The stance of NutritionFacts is that K2 from our gut bacteria is sufficient to supply our needs. K2 research is in its infancy, so I think it is wise for NF to take a position that is skeptical of the extravagant claims that are being made for supplementation.

                  That said, since it does no harm to make and consume natto, I will continue to enjoy it on its own merits. Its abundant K2 may also be proven someday to be beneficial. That’s how I choose to hedge my bets on this one.

                  1. Thank you, plant_this_thought, for your helpful reply. As my post above showed, I wasn’t familiar with the vitamin K info discussed by the other posters here. Thea’s mention of the linked article at veganhealth.org was timely and really helped me understand the difference btwn. K1 and K2. Thanks for pointing out the difference again, and for your thoughts on consuming natto rather than supplementing K2 at present. Next up for me–trying out some natto!

                    1. I tried it once and it was absolutely disgusting. But I am all for trying to develop a tolerance. But I need some genius way to hide the natto until I can aquire a taste.

                  2. I agree that in principle I should be getting enough K2 from K1, by means of gut bacteria. But I have no way of knowing how well that’s actually working. I don’t eat only organic produce, which means I probably consume some glyphosate, which does a job on gut bacteria. So I prefer to err on the side of caution on this one. Unfortunately, I find natto hard to eat. Since the MK7 K2 supplements are from natto anyway, to me it’s not different from using algae-sourced DHA supplements. The amount of MK7 in these supplements is tiny, 200 mcg or so.

                    I do hope there is more science soon. Here’s an intervention study of K2 supplementation and bone loss. https://www.ncbi.nlm.nih.gov/pubmed/23525894

                    1. I take Dr. Fuhrmans men’s multi vitamin. It’s designed for plant based eaters and he does put a little MK7 in there. I guess he is also erring on the side of caution. He also puts some taurine in it even though our bodies should be able to synthesize that nutrient as well.

                    1. nc54: I’m glad you asked! I’m a bit of a fanatic on the subject of natto.

                      First of all, homemade natto is a far cry from the frozen stuff you get from the Asian market. It takes a while to learn how to make it, but once you do, you’ll become a snob like me.

                      Secondly, natto is not something most people find enjoyable by itself. It needs something acidic to cut through its strong musky, funky flavor. The classic condiment is Dijon mustard. If I was introducing someone to natto, I would put it on some whole wheat toast with a smear of hot mustard and some broccoli sprouts. The natto provides an unbeatable earthy, sensual umami that grows on you.

                      Natto is sort of like beer, or red wine, or kalimari

                    2. Put it in vegetable soup – that dissipates the sticky gel coating.
                      It’ an acquired taste.
                      If you like miso then you add it to miso/vegetable soup (small amounts only at first).
                      I keep it in the freezer, cut off a block and throw it in the centre of the bowl when I serve it, that way it doesn’t get boiled with the soup.

                  3. I hedge my bets by including cheese and sour cream plus supplemental K2. I also try to regularly include large amounts of cilantro and parsley in the diet. I wanted natto to be passable but it was just too nasty. I don’t see a risk in a higher level intake of menaquinone. The following is what informs my view:
                    “These findings suggest that dietary intake of menaquinones, which is highly determined by the consumption of cheese, is associated with a reduced risk of incident and fatal cancer.” PMID: 20335553

            2. WFPBRunner, just saw it; thanks for pointing it out! Between that and Thea’s new comment below, my thoughts are that a WFPB, SOS-free diet helps our bodies make enough K2 to be protective against against hypercalcemia. I love this website and interaction with knowledgable, thoughtful posters (like you and Thea!). Thanks again!

      2. Yes, Dr. Mcdougall says not to supplement and that vitamin D3 is linked to pancreatic cancer and prostate cancer. It’s so confusing and scary not truly knowing what is correct. I’m freaking out.

        1. Hi I’m a moderator with NutritionFacts. Thanks for your great question. I love Dr. McDougall. I watch him on youtube all the time. He is not against supplementation of Vitamin D completely. The point is not to supplement unnecessarily. Ideally, we would get all the Vitamin D from the sun. I live in Wisconsin so that is not happening during our winters. So if you need to supplement, only take what is necessary to keep your Vitamin D level adequate. Sometimes with supplements, our attitude seems to be, if a little is good, massive mega doses are better. And of course that is not the case. I would ask your doctor to check your vitamin D level. If it is adequate, you may not need to supplement at this time. But if your level is low, that is a bigger risk than supplementation. If so, take enough to get to a normal level. This is the NIH recommended amount:
          Life Stage Recommended Amount
          Birth to 12 months 400 IU
          Children 1-13 years 600 IU
          Teens 14-18 years 600 IU
          Adults 19-70 years 600 IU
          Adults 71 years and older 800 IU
          Pregnant and breastfeeding women 600 IU

          A lot of supplements have 2000-4000 IU of Vitamin D which is much more than most of us need.

          NurseKelly
          Moderator.

    2. Very good post Todd. I could not agree more with the idea of using results as the relevant factor. I don’t remember the source but I did see a study a few years ago showing that supplements were between 30 and 70% of the actual strength they claimed. “Good” brand or generic seemed to make no difference. I think this only makes the case for watching blood levels more imperative since the supposed dose is only a wild approximation.

      At one time I had about 17 ng/ml and I was taking 1500 units per day. Who knows what the actual dosage was. Now I take what the label says is 5000 units and my level is around 60. That gives me enough stored so that I do not worry about being indoors a few days and leave the supplements at home.

      1. @disqus_D6pSBYB08L:disqus When I started supplementing, I did some searching about which brands were tested and how accurate their labels were. I learned that one brand, “Nature’s Bounty”, widely available in the US, was found to be reliable in having the actual amount of D indicated on the label, so that’s what I use. It’s inexpensive too.

        1. I was also wondering about looking into Nature’s Plus vitamin D as every Nature’s Plus supplement I’ve purchased comes with a certificate of analysis. The results show the actual amount of the vitamin in the batch you purchased, done by an independent lab.

    3. This is informative – thank you for pointing out the difference between Nol/1 and ng/ml. So if my level is 45 ng/ml, does that meet Dr. Greger’s suggestion? Thank you!

    4. Todd, thanks for bringing up all this info! I was already aware of these and glad someone brought that up. I am amased as most doctors still do not recognize the latest work and research, specially the ones from M. Hollick. I am glad Dr. Greger is not tied to the old school knowledge about vit.D.

    5. Yes, Dr. Mcdougall says don’t supplement and that it is linked to pancreatic cancer and prostate cancer. It is confusing and scary not truly knowing which is correct. Dr. Wolfe ssys to take 15,000 a day. I’m freaking out. Help!

  4. Dr. G. does a great job here of explaining some difficult epidemiological concepts, using easy-to-understand examples. If we don’t understand these concepts, it is easy to get mislead — which unfortunately is sometimes done on purpose. These are:
    1) the difference between correlation and causation: causation is MUCH harder to prove.
    2) confounding or “lurking” variables: when the data show that “B” is correlated with “C”, but it turns out that there is a third variable “A”, which causes both “B” and “C”.
    3) “reverse causation” — which means when it looks like A causes B, but it turns out that B causes A. That points out the importance of having either experimental or cohort studies, where you know which one happened first — i.e. if B always happens before A, then it’s tough to say that A causes B.
    4) randomized controlled trials: He doesn’t explain here exactly what that means. A “trial” means you are doing a study which compares two treatments, say, the mortality of people who take Vit D supplements vs. those who don’t. “Controlled” means you try to make sure people in the two groups are similar in every way possible, especially regarding variables known to be likely to affect the outcome, such as age, gender, smoking status, etc. “Randomized” means that the study participants don’t get to choose which treatment group they’re in; they get randomly assigned. This is a great way to control for possible sources of bias.

    Learning some of these concepts helps to better understand what we read.

        1. Cool, thanks – That is informative. I don’t totally understand the p-value and will look for a statistics 101 video to explain it to someone who has never taken statistics :-).

          1. Sharon: The p value of a study is the probability of its conclusion to be a fluke. For example, say the p value of a study is 0.01. Multiply it by 100 and you get 1, meaning that the chances of the conclusion the investigators have made being a fluke is 1%. In general, 5% is considered the threshold, meaning if the p value of a study is 5% or higher, its conclusion has no statistical validity.

            1. Thanks for that. Now that’s easy to understand :-). I’m a web designer and in my original comment I was looking at the user experience – in order to understand terms (defined by Dr.Jon_NF Volunteer above and used by Dr. G. in the video and many other videos) you would have to pause the video, exit the website and Google the terms – which is unwise design. Terms should always be defined so as not to give the user the excuse/reason to exit your website. I mean, that’s what I was thinking.

              1. Good point, and I like your idea of having a place where epidemiologic terms are defined — e.g. on a FAQ page. I will propose it to folks at NF.

    1. I would like to see a controlled experiment in which the protective benefits of vitamin D supplementation were directly compared to UV exposure. Or maybe repeat the study with UV dosimeters given to the subjects, in order to see whether some additional protection is conferred by sunlight. Maybe vitamin D is the whole story, or maybe just part. Maybe, for instance, sunlight exposed people, in addition to having higher vitamin D levels, are less depressed, and happier people have better working immune systems and lower disease rates, etc.
      It would be surprising (but, of course, not impossible) if a pill turned out to be the perfect equivalent of sunlight. Experience teaches us to be wary of reductionism, and the video does a good job of discussing the problem of confounding factors and lurking variables.

      Meanwhile, the benefits of vitamin D supplementation are undisputed, and I am grateful for this option, as I look forward to another Minnesota winter!

      1. I wonder about this too, plant_this_thought. How important is it that I carefully fry my skin every summer? Even with 10 minutes of noonday sun 3x/week, I have noticed a small amount of sun damage emerging that I’m not crazy about.

        1. As a 50-something redhead who “fried” in her teens, I wonder the same thing! Family members (including one younger than me) have been diagnosed with basal cell carcinomas, so I’m concerned.

          1. Different areas of the planet and different times of the day have varying intensities of sunlight. This is why in Australia they tell people to stay out of the midday sun. I think it’s banned from 10am to 2pm. This is when the burning rays are the most intense since the sunlight has different types of rays. UVB and UVA. It is a conundrum re: how to shield ourselves from danger but still get enough to make Vitamin D. I personally make sure the areas that get the most unintentional sun exposure – face, forearms – always have sunscreen. Then if I go out with bare legs or a bare arm I don’t put sunscreen on unless its a whole day affair so I can hopefully make some Vitamin D. I’m still low so I take a supplement, too but am happy my Irish heritage skin living in So Cal has not had anything grow that needed to be taken off thus far. So, like most things moderation is probably key. No noonday sun, judicious use of sunscreen, Vit D supplement and monitor with blood tests.

            1. @docbeccy:disqus The “dminder” app that I mentioned is very clever about helping you to avoid overexposure. It detects your location and uses that and the time to calculate the position of the sun in the sky, to determine your actual UV index. In the profile setup it asks you to choose your skin tone from a series of images. For example, as I write this at about 9:00 am in Philadelphia, it tells me my next “D opportunity” is in less than two hours, from 10:28am to 3:00pm. Before or after that, I can’t get enough sunlight to make D or burn.

              If I choose to sunbathe, I just tap an icon to start the session. Based on my skin type, age, etc, it will tell me when I’ve had enough and should either “turn over” or cover up and get out of the sun. And it will tell me how much D I’m producing from that session. It’s really a well thought-out app.

            2. I’ve read (Re: Vitamin D Council) a simple test, a rule of thumb, that can be used to gauge the ability of sunlight to make vitamin D: If your shadow is shorter than you’re, your body can make vitamin D; if it’s taller, your body can’t.

      1. Right you are; I actually Googled “misled” when I posted, and convinced myself it was “mislead”; I have since realized my mistake.

  5. That’s dr G.’s hallmark.
    If want more good laughs I would recommend watching some earlier videos by dr Greger, especially the annual summaries. Also videos on Youtube featuring him from some earlier years are good (I’d call it a very expressive body language which is good because nobody does it like dr G. :-) ).

  6. Be care with across the board recommendations. After trying to boost my vitamin D levels, I discovered that vit D boosts testosterone. Normally a good thing, unless one is combating prostate cancer, in which case you are feeding the cancer!

    1. Hi, what happens if our testosterone levels are high and we are females?
      I do take 5000IU D3/per day, and have been very agitated and also less tolerable temper, is that the high D levels maybe :-( ????

        1. Thank you Thea, yes that is a staple tea in the Middle East, but long forgotten since living in Australia.
          Will get back onto it. Thanks so much for your reply and suggestion.

  7. Dr. Gregor, I’m a huge fan of your work and want to see this research reach people all over the world. Would you be interested in having your transcripts translated to German? If so, please contact me at ronct29@gmail.com

  8. Wasn’t there a story in Freakanomics correlating ice cream sales with polio in the 1920’s, under the heading; Correlation does not mean Causality. I think a toxicologist years ago linked broccoli consumption with cancer risk, more as a warning about statistics than broccoli.

  9. When I supplemented with 2000 IUs of D-3 a day, my levels were in the 75-80 range. When I dropped to supplementing with 1000 IUs a day, my range fell to around 45. Therefore, I am back to 2000 IUs.

    1. That’s what everyone should be doing since the upper limits for toxicity is pretty high. Test, adjust, retest. This one is not a major stresser.

  10. Dr Gregor I’m a huge fan of your work… but as a women’s health nurse practitioner it bothers me that you keep citing the women’s health initiative study that was found in many ways to be very flawed research. Please update your knowledge about hormones…look at the recent ELITE trial… the type of hormones used make a big difference on risk….hormones…when started close to menopause have no cardiovascular risk associated with them….I’ve seen you cite this study as an example of people making assumptions about safety without the studies to prove it… I would use a different study if I were you…much of what it concluded has been modified or disproven.

      1. Hodis HN, Mack WJ, Shoupe D, et al. Testing the menopausal hormone therapy timing hypothesis: the Early Vs Late Intervention Trial with Estradiol. Circulation. 2014;130:A13283.

    1. Hi Jean
      I was looking for something that says the woman’s health initiative is flawed.
      Are you saying you recommend woman in early menopause start HT? Both studies have value as they add to our knowledge of HRT and CVD.

      It adds information to our knowledge but here is a letter regarding the study–
      “This provides reassuring news for women in early menopause who are considering hormone therapy for management of menopausal vasomotor symptoms. However, it really shouldn’t be used as a rationale for long-term use of hormone therapy for chronic disease prevention, because there are other considerations, including the potential for increased risk for stroke, venous thrombosis, and gallbladder disease, and with estrogen plus progestin there is an increased risk for breast cancer.

      The evidence does support the timing hypothesis. We need more research using other formulations of hormone therapy, such as transdermal estradiol, and lower doses of hormones. We look forward to additional research in those areas as well as seeing the final results of the ELITE trial.”
      http://www.medscape.com/viewarticle/837535

    2. I just listened to the podcast version of this article on menopause and HRT; it was interesting. The Wellcome Trust is a foundation that has ties to the pharmaceutical industry, but I found the reporting to be fair. I might be biased since I used to work in a medical history library and The Wellcome Trust sponsors a lot of programs and research in medical history – laudable since we can learn so much from past errors as well as successes.

  11. My daughter is 12 yo and has a low Vit D 28 ng/ml level. Her weight is 90 lb and she is vegan. Could you please recommend the dosage and in which form (liquid or capsules). Thank you.

    1. Hello Viktoria, I am a volunteer for Dr Greger. Welcome to the site! You’ll find a robust discussion here about Vitamin D. I recommend you view the other videos dedicated to Vitamin D to make a decision on dosage, or work with a progressive health care provider to gain support. Always recommend guidance from a physician, naturopath, or pediatrician for dosage information. Good luck!

  12. I switch between Dr Greger’s advice on this one and Dr McDougall, which vehemently warns against using Vit. D. Presently, I trashed my vitamin D. I’m in Vermont so I make it a point of trying to get more sun during the critical months.

    I don’t know or understand how these two fellows could have such opposed views on something like this. Echos their difference on potatoes.

    1. Tobias does Dr. McDougall post the various research articles that has led him to make that claim? I was listening to a video he once made where he was talking about D and his windsurfing and being outdoor. But again I prefer current research articles. There is a difference, as you know, from an opinion. Which hopefully has become a very small part of practicing medicine. (Evidence based practice)

      1. I expect that McDougall partly bases his judgement on the likely fact that all of the studies Dr Greger cites are likely conducted on unhealthy people to begin with.

    2. It would be more surprising to me if Drs Greger and McDougall agreed on everything. That said, I side with Dr Greger and the studies he cites when it comes to sodium, i.e., put the salt shaker down. When it comes to potatoes I side with Dr McDougall. In fact Dr Greger’s “favorite nutritionist”, Jeff Novick, points out that the negative health findings for potatoes were survey studies and didn’t account for the oil, butter, sour cream, bacon, and salt that Americans normally put on their fried, mashed, or baked potatoes. By the way, Jeff Novick also details the positive nutritional value of iceberg lettuce that Dr Greger should read so he can update one or two of his oldest videos.

      Regarding Vit D, I will watch carefully for the story to unfold at NutritionFacts.org because reading and analyzing the current literature is Dr Greger’s main focus.

        1. Not sure what you mean about “lots of study on unhealthy people.” Yes, today’s video is about cancer and Vit D. But Dr Greger
          has lots of other Vit D information. Try these two videos for healthy people:
          http://nutritionfacts.org/video/how-much-vitamin-d-should-you-take/
          http://nutritionfacts.org/video/the-optimal-dose-of-vitamin-D-based-on-natural-levels/

          Or this page for links to all his Vit D videos.
          http://nutritionfacts.org/topics/vitamin-d-supplements/

  13. We have to take a look at this study in detail:
    N Keum, E Giovannucci. Vitamin D supplements and cancer incidence and mortality: a meta-analysis. Br J Cancer. 2014 Aug 26;111(5):976-80

    1. Only (!) 3 RCTs for total cancer mortality included. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4150260/figure/fig2/

    “the small number of included articles is likely to have negative effect on credibility of the meta-analysis”
    https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4580385/

    2. No benefit for the prevention of cancer: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4150260/figure/fig2/

    3. This study was not mentioned (!):
    Meta-analysis of three randomized trials evaluating the effect of vitamin D supplementation on overall survival in advanced prostate cancer patients: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3228169/figure/F2/

    4. This study was done a year later:
    https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4603640/

    Therefore: This video is outdated already.

    1. Hi Matevz,

      After reading your post I did some checking and I find out that most of the research that does not associate low level of vitamin D with cancer has used no more than 75 nmol/l in the experimental group, this value is considered upper limit for deficiency by recent studies, there are already organizations that consider 150 to 200 nmol/l, so I am puzzed that research work still consider the old school value for a normal range of vitamin D.

      “…Using these functional indicators, several studies have more accurately
      defined vitamin D deficiency as circulating levels of 25(OH)D ≤ 80 nmol…”
      http://jn.nutrition.org/content/135/2/317.short

      In a quick search I found some recent 2016 papers:

      “..Results: Men with higher serum 25(OH)D were less likely to die from their prostate cancer…”
      http://cebp.aacrjournals.org/content/25/4/665.short

      “…Conclusions 1,25(OH)2D3 has protective effects against CRC through the regulation of stromal fibroblasts…
      http://gut.bmj.com/content/early/2016/04/06/gutjnl-2015-310977.abstract

      “…We show that vitamin D signaling inhibits the expression of the tumor progression gene Id1…”
      http://press.endocrine.org/doi/full/10.1210/en.2015-2036

      “…Conclusions: Genetically lowered 25-hydroxyvitamin D concentrations were associated with higher ovarian cancer susceptibility in Europeans. These findings suggest that increasing plasma vitamin D levels may reduce risk of ovarian cancer…”
      http://ije.oxfordjournals.org/content/early/2016/09/03/ije.dyw207.short

      “…Our findings suggest a protective role of vitamin D in lung cancer, with stronger associations observed for D3, and reinforce the importance of maintaining optimal levels of this crucial vitamin for human health…”
      http://cancerres.aacrjournals.org/content/76/14_Supplement/4320.short

      1. You have to be careful when you’re searching for relevant studies – Greger’s topic in this video are supplements and his strongest study was the one I’m criticising. Note:
        – Power of sunshine (and sunshine-related difference in lifestyle) is not the same as the power of a supplement. Side effects are different, too.
        – Hierarchy of evidence: meta-analysis of RCTs is not the same as meta-analysis of prospective studies; one isolated study doesn’t have as much power as a meta analysis or unbiased review
        – Watch out for conflicts of interest (Supplement companies)
        – I suggest that you do not aim for 150-200 nmol/L if you’re using supplements; if you reach this range just with sunshine, it’s OK.

        2010 – An Evidence-Based Analysis:
        “For bone health outcomes, no high or moderate quality evidence could be found to support a target serum level above 50 nmol/L. Similarly, no high or moderate quality evidence could be found to support vitamin D’s effects in non-bone health outcomes, other than falls.”
        https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3377517/

        2011 – van Schoor & Lips:
        “Most investigators agree that serum 25(OH)D should be higher than 50 nmol/l, but some recommend higher serum levels”
        http://www.bprcem.com/article/S1521-690X(11)00071-6/abstract

        2013 – Optimal Vitamin D Status: A Critical Analysis on the Basis of Evidence-Based Medicine:
        “Effects on cancer, immune diseases, and infections or cardiovascular and metabolic risks or events are not firmly established so that optimal serum 25OHD levels for such extraskeletal effects cannot be defined.” ”As long as RCTs have not formally proved causality, there is still a possible scenario of reverse causation” ”The principle of “primum non nocere” should restrict the use of higher than recommended dosages of vitamin D for the general population, pending further proof of efficacy and safety in RCTs.” ”Using RCTs as the main guideline, we can conclude that serum levels of 25OHD above 50 nmol/L are sufficient to normalize calcium and bone homeostasis as measured by surrogate endpoints such as 1,25(OH)2D, PTH, calcium absorption, or bone mass.” ”The recommendations for a daily intake of 1500–2000 IU or serum 25OHD levels of 75 nmol/L or higher for all adults or elderly subjects, as suggested by The Endocrine Society Task Force, are premature.”
        http://press.endocrine.org/doi/10.1210/jc.2013-1195

        2014 – Observational studies vs RCTs:

        “Observational studies have identified links with several diseases, but
        these have either not been evaluated or not been replicated in randomised
        controlled trials. Randomised controlled trials for autoimmune and cancer
        related outcomes are clearly lacking. In addition, earlier evidence from
        randomised controlled trials that vitamin D supplementation (with or without
        calcium) increases bone mineral density and reduces the risk of fractures in
        older people is not seen in clinical trials that examine vitamin D only
        supplementation.” https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3972415/

        2014 – What is the optimal level of vitamin D?:

        “For patients at high risk of poor bone health or colorectal cancer,
        accepting the potential risks of higher 25(OH)D levels may be warranted to gain
        the possible benefits. This is a judgement call that physicians must make in
        consultation with an informed patient. Apart from these high risk groups, there
        is no strong evidence to support health benefits of vitamin D supplementation
        for those with apparent mild insufficiency (40–50 nmol/L) on routine
        testing.”

        http://www.racgp.org.au/afp/2014/march/vitamin-d/

        2015 – Measuring vitamin D:

        ”A 25-hydroxyvitamin D threshold of at least 50 nmol/L at the end of winter is
        a suitable treatment target.”

        https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4654047/

        2015: Predictor of Health Outcome or Marker of
        Health Status?:

        “Finally, while our review focused on extraskeletal complications and
        discussed the related challenges, this debate might not remain limited to
        extraskeletal complications for long but may soon include skeletal
        complications. Indeed, recent evidence has suggested that vitamin D might not
        be as essential as previously thought for maintaining bone health and
        preventing falls [64–66, 124]. Vitamin D (the solar vitamin) is likely to
        remain a burning topic in coming years.”

        https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4436443/

        2016 – Stokes & Lammert: “Currently, optimal serum vitamin D
        concentrations are controversial, and there is a discrepancy between two key
        guidelines. The Institute of Medicine recommends 20 ng/ml (50 nmol/l; 1 ng/ml =
        0.40 nmol/l) as adequate on the basis of bone health studies, which is in
        contrast to the 30 ng/ml (75 nmol/l) urged by the US Endocrine Society. To achieve levels of the
        latter, approximately 4,000 IU of vitamin D would be required daily. However,
        the safety of such a dose needs to be confirmed in further controlled trials,
        as, for example, a higher risk of upper respiratory tract infections has been
        reported with 4,000 IU of vitamin D per day in asthma patients achieving
        circulating 25-hydroxyvitamin D levels of more than 30 ng/ml (75 nmol/l).”

        https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4991525/

        2016 – Vitamin D and extra-skeletal health:
        causality or consequence:

        “Unless more evidence of clinically meaningful effects of supplementation
        is available, it may be too early to recommend for or against vitamin D
        supplementation for maintenance of extra-skeletal health and prevention of
        disease, beyond the daily requirements for calcium homeostasis and skeletal
        benefits.”

        https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5003588/

        >125 nmol/L: Emerging evidence links potential adverse effects to such high levels, particularly >150 nmol/L
        https://ods.od.nih.gov/factsheets/VitaminD-HealthProfessional/

        An indirect mechanism through which vitamin D may increase prostate cancer risk: http://onlinelibrary.wiley.com/doi/10.1111/cen.13062/abstract

  14. The best thing about this video was that it explained a lot about statistics and how they can be misinterpreted. Great explanations and examples Dr. G.

  15. Vitamin D is made from Carbon and hydrogen. Could it be the diet’s source of Carbon? Could it be a backbone for genes, since it activates so many? Cancer patients with the highest levels of vitamin D lived the longest, according to several reports including on on the Vitamin D Council’s webpage. Could Carbon be deposited on your skin by sunlight?

  16. I have increased eye pressure, open-angle glaucoma, what can I do? Please dr.Greger, make a video about Glaucoma and how not to get blind. My Iphtalmolog gives me Ganfort .Thanks.

  17. I am a melanoma survivor having grown up in Australia, 1940’s-60’s before suntan lotion and with fair skin. I take Vit D supplements. But do you think dermatologists prescribing no sun at all for those with average skin cancer risks have gone overboard increasing deaths from multiple cancers though saving a few from skin cancers, many of which carry lower morbidity and mortality than colon and other cancers?

    1. Dear Robert Haile, When I read your post, I instantly thought of a lecture I had seen on the university of calif tv channel given by Dr Alexander Wunsch on the historical perspective of sun exposure.. http://www.uctv.tv/shows/Why-the-Sun-is-Necessary-for-Optimal-Health-29076 it made a strong impression on me at the time. I thought of it too when Dr Greger posted a video about sunlight and photosynthesis. I will try to find it and post it here for anyone interested.

        1. Does the sunlight have to be an hour or so after eating greens? What about if you eat greens before bed, then the next day would you still have enough in your bloodstream when out in the sun?

          1. I am sorry nc54, I do not know the answer to your questions, though I find the whole topic so fascinating. Since I first saw that video of Dr Greger’s, it has been on my mind, and more than once I ate a big salad or beans ‘n greens purposely for lunch before working in the garden, or going for a walk or swim. I hope we will learn more in future!

  18. What about people live near the equator and with plentiful sunshine? Some studies showed they were healthier.
    What about the sharp contrast of disease including cancers between people who lived on island of Crete and Karpathos? The two islands are geographically close to each other. They have the same environment and the same diet. One difference between the two is the dirt/ground. Crete is made of basalt rocks and Karpathos of lime stones.
    We should not focus on just a few factors.

    1. I think that you have firmly gripped the wrong end of the stick here.

      Magnesium deficiency is reportedly significant more common than excess magnesium
      “Magnesium deficiency can cause a wide variety of features including hypocalcaemia, hypokalaemia and cardiac and neurological manifestations. Chronic low magnesium state has been associated with a number of chronic diseases including diabetes, hypertension, coronary heart disease, and osteoporosis.”
      https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1855626/

      1. those on veg and fruit bean grains diet unlikely to be deficit in magnesium.

        ;;;;;;;;;;

        Americans sure do love their vitamins and supplements. Every year, we
        spend a whopping $20 billion on them. But if you think all that cash is
        going to buy you a longer life, think again. A new study in this week’s
        Archives of Internal Medicine suggests that some supplements may
        actually shorten your life.

        In the study, researchers used information from 40 thousand women who
        filled in questionnaires several times over the last 22 years. They
        answered questions about all sorts of health issues, including
        supplement use.

        Matching this data to records from the state health registry and the
        National Death Index, the researchers identified seven supplements that
        actually seemed to be hastening death. Those include vitamin B6, folic
        acid, iron, magnesium, zinc, copper, and even your innocent-looking
        multivitamin.

        1. “those on veg and fruit bean grains diet unlikely to be deficit in magnesium”
          Yes but they may be deficient in Vitamin D. And not everybody is on a veg, fruit, beans and grains diet.

          In any case, I doubt whether the tiny amounts of magnesium found in some vitamin D supplements will have a noticeable effect one way or the other. The tolerable upper limit of magnesium from supplements is 350 mg per day.
          https://ods.od.nih.gov/factsheets/Magnesium-HealthProfessional/

          What is more, as far as I know, no “vegan” vitamin D supplement contains any magnesium whatsoever. To be frank, I am not aware of any vitamin D supplements at all that contain magnesium (but haven’t looked at too many non-vegan ones). If you are claiming vitamin D supplements contain magnesium, then you need to prove it.

          Sorry but your original comment was and is badly wrong.

          1. You won’t typically find Mg in with D or in any large amount in a multi since it takes up a lot of room. I tried supplementing with magnesium citrate for sleep benefits and found the large pills difficult to swallow; I tried the powder but found it unpalatable. I try to get my Mg (which is important for overall health) from food now – mostly from lentils and some other legumes, pumpkin seeds, almonds, spinach and tofu (which also has calcium). I worry there might be a bolus effect from Mg supplements, as is the case with calcium. I found other ways to improve my sleep (time restricted feeding, early morning light exposure and contrast showers).

            1. Yes but I think that he is alluding to magnesium stearate which is a widely used as a binder/filler in tablets including supplements.

    2. I take B12 and 1000 Vit D , as well as 200 mg mag gluconate. that’s it. And I wouldnt trade the magnesium for anything! I dont care for taking supplements, but i gladly mix mag powder in my oatmeal with cinnamon daily . Such a noticable difference in how I feel. No foot cramps ! No restless leg syndrome! Better performance swimming!

  19. Insufficient vitamin D is linked to virtually every age-related disorder including cancer,1-11 vascular disease,12-17 and chronic
    inflammation.2,18-23 Adults (and children) with higher vitamin D levels contract substantially fewer cold, flu, and other viral infections.24-26
    http://www.lifeextension.com/magazine/2010/1/Startling-Findings-About-Vitamin-D-Levels-in-Life-Extension-Members/Page-01

    I love the company’s research findings. I don’t financially benefit from LEF. I do purchase majority, but not all supplements from them.

    Vitamin D slows Parkinson’s progression
    http://www.lifeextension.com/Newsletter/2013/3/Vitamin-D-Slows-Parkinsons-Progression/Page-01

    Reduced childhood vitamin D levels predict diabetes
    http://www.lifeextension.com/Newsletter/2011/12/Reduced-Childhood-Vitamin-D-Levels-Predict-Diabetes/Page-01

    Maintain vitamin D: maintain independence
    http://www.lifeextension.com/Newsletter/2012/6/Maintain-Vitamin-D-Maintain-Independence/Page-01

    Vitamin D improves cardiac syndrome X
    http://www.lifeextension.com/Newsletter/2014/4/Vitamin-D-Improves-Cardiac-Syndrome-X/Page-01

    Reduced vitamin D associated with decreased cognitive function
    http://www.lifeextension.com/Newsletter/2013/6/Reduced-Vitamin-D-Associated-With-Decreased-Cognitive-Function/Page-01

  20. Vegan Vitamin D 3 seems to be from lichen . Looking at lichen under wikipedia , it seems to have a long history of use by both europeans and north american natives, sometimes as medicine, sometimes as emergency food or as a thickener. I found it interesting it has been studied to have a potential in treating mad cow disease. It’s also considered to be the longest living “thing” on earth.
    Wonder if a whole food could be made from lichen and still have the vit D3 and other benefits?

  21. Dr. Greger, my understanding of HRT studies that showed increased mortality rates, is that the higher rates were closely associated with those who started HRT over a certain age (like 55 or something), but those who started it earlier didn’t have this increased risk so much. Any insight into this?

  22. I just finished How not to die and I was wondering if there is any evidence of vitamin deficiency or hormons when hair loss? I have been loosing hair since 12-13 years old, now I am 22 and the amount of hair falling is still high. I am deficient in iron and I have prescription pills from my doctor, but it does not seem to work. To be clear my hair falls out a lot, but still grows new hair, so my hair is thinner at the end. I have been vegan for an year and do not see any difference in hair neither improvement nor worsening.

    At the end I want to tell you how much I love your book. I have been recommending it since to everyone and it is life changer. Greetings from Czech republic.

    1. Monika: What a frustrating problem to have. I don’t know if it will help or not, but following is a link to an article from Jack Norris who talks about the link between thyroid problems and hair loss–and how a change in diet may bring a thyroid problem to the fore. Other potential issues are also listed. http://jacknorrisrd.com/category/hair-loss/ Specifically note: “Summary: Occasionally, women who become vegetarian or vegan report experiencing hair loss. If there is a dietary cause, the most likely are rapid weight loss, thyroid problems, or iron deficiency. Zinc deficiency and not getting enough of the amino acid lysine could also be culprits.”

      For the full article where Jack goes into lots of detailed information, check out: http://veganhealth.org/articles/hairloss

      Good luck!

  23. For additional information I would recommend the following NF.org video’s:
    http://nutritionfacts.org/video/the-best-way-to-get-vitamin-d-sun-supplements-or-salons/
    and
    http://nutritionfacts.org/video/the-risks-and-benefits-of-sensible-sun-exposure/.
    The best way to get Vitamin D is sunlight exposure since it has other benefits such as improved blood pressure due to increased nitric acid in the blood. As other posts pointed out you have be clear about nmol/L vs. ng/ml.
    I would caution about the thinking “if a little is good alot is better” approach as toxicity is observed above 100 ng/ml. Isolated supplements don’t have a good track record as they related to recommendations for healthy populations especially for other fat soluble vitamins such as A and E.
    See video: http://nutritionfacts.org/video/antioxidant-vitamin-supplements/
    I prefer not to talk about optimal levels. In complex or adaptive systems you provide input such as a supplement or food and your body adjusts with a range of outcomes. There are often surprising or unanticipated consequences. They can be helpful or harmful. To further complicate the matter is the issue of variation between individuals which brings in a somewhat humbling consideration of “what is normal?”. Not easy for clinicians to answer for specific individuals since the “normal” levels are derived based on measurements of specific populations.
    At this time for myself I think the science supports: sunlight is best, Vitamin D supplementation at 2000 IU a day is reasonable. If you are checking blood levels a target above 30 ng/ml or 75 nmol/L seems reasonable. That said there are examples of individuals with plenty of sunlight exposure but levels below 30 ng/ml. You need to keep subscribed to NF.org as the science keeps coming.

  24. Ever since learning that a large part of the population is vitamin-D deficient, I have been wondering how Europeans were able — up until a supplement started being marketed — to achieve adequate levels of the vitamin and thrive despite local weather. Even considering that early Europeans must have spent longer times outdoors than their modern descendants, they must have worn long, thick clothing for a substantial part of the year. Also, dark-skinned gypsies have been living in Europe for hundreds of years. How is this possible?

    1. maor_b That’s a good question. I think the answer is simple: They got their D (and K2) in animal foods such as butter, egg yolks, and fish. UV-exposed mushrooms were also a possibility, but I’d expect them to have the same problem of inadequate sun during much of the year. This is the sort of thing that Weston Price’s research sheds some light on. He found that Europeans in Switzerland and Scotland, for example, who were largely isolated from the effect of processed foods had excellent bone and dental health, which was lost in a single generation when these people changed their diets. He used a blend of pastured butter and cod liver oil to help them restore their health.

      Fair skin is an adaptation to increase D production, but it obviously can’t work in climates where temperature forces people to cover their bodies most of the year. In those climates, dietary D is the only option and historically that would have had to come from animal foods. Today, of course, there are other options. It’s also possible that darker-skinned people have adapted to lower D levels: http://www.circumpolarhealthjournal.net/index.php/ijch/article/view/18001

      Whether the risk curve is really U-shaped is still disputed, from what I read.

      1. Hi Todd, your reply makes me wonder whether animal foods such as butter, egg yolks, etc could be reliable vitamin D sources, or was it the combination between some sunlight exposure and dietary sources? While it is known that Inuits received their vitamin D by ingesting seal liver, it is mentioned in many vegan resources that sufficient levels of vitamin D cannot be obtained by consuming animal foods. I am quite surprised that previous generations of Europeans had excellent bone health, since animal foods are acidic and leach calcium from the bones.

        The study you linked to does remind me reading an article on the Weston Price website, saying it is possible that different races need different levels of 25(OH)D in their blood, due to genetic efficiency or lack thereof in converting it to calcitriol, exactly as mentioned in the link. This is interesting and makes one wonder how reliable blood-test ranges are.

        1. @maor_b:disqus Obviously, vitamin D alone can’t correct a calcium deficit, but the fat-soluble vitamins D, A, and K2 work together to regulate calcium absorption and utilization. Certainly any sunlight exposure at all would be helpful. Beef liver is also a decent source of D, as well as other vitamins, since livers act to accumulate and store various nutrients. Liver is also fairly starchy, due to stored glycogen. Ruminants get their D by eating green grass etc. Mammalian liver would always have been available, as well as eggs. If you go to http://nutritiondata.self.com/foods-000102000000000000000-2.html? you’ll see that the best sources are marine animals, followed by artificially fortified foods. You have to scroll quite a bit to get to mushrooms, which would have been only very intermittently available, and eggs. So if you ask yourself where isolated Swiss villagers or in the 1920s were getting their D, the only possible answer is, for most of the year they were getting it from milk fat (in various forms), eggs, and organ meats. The Outer Island Scots, also studied by price, ate mainly seafood, root vegetables, and oats, supplemented with some goat milk products. There’s not a lot of direct sunlight for making D up there, but Price reported (and photographed) excellent bones and teeth and robust health…until they started to import civilized foods.

          In a way, Price was the original “blue zones” researcher.

  25. I have read in numerous places, even on the back of some of the bottles of supplemental Vitamin D, that taking higher levels of Vitamin D can harm your kidneys.
    So is this accurate?
    If you are saying there’s no credible evidence of harm, why has this been not only written about in many places, but even put as a warning on the bottles?

    1. @luckymidnight:disqus I think the more answerable question is: What is the evidence for harm to the kidneys, and at what dosage levels? Here, https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2878736/ is a study that suggests higher D levels as part of treatment for people with kidney problems.

      I’ve read that there are only a few documented cases of actual vitamin D toxicity in all of medical records, and these involved accidental intakes of millions of IUs, but I’d have to go hunting to find the reference for that. And that doesn’t mean that truly high doses are optimal. Some sources say that daily intake of 40,000 IU or more is problematic, but that’s a lot more than most people even contemplate. Other sources say that a blood level over 200 ng/ml is considered toxic, but hardly anyone gets that high.

      I’ve also read that the skin *stops* producing D when a certain level is reached. I don’t remember what that level is, but it’s well above 30. I want to say it’s around 80, but I may be wrong.

  26. According to a summary of the research on ConsumerLabs.com (like NutritionFacts.org, a great source for nutrition information), several studies have shown negative consequences to levels of vitamin D above 30 ng/ml. The CopD study (population study following 200K+ people in Denmark) found vitamin D levels of 20-24 ng/ml had the lowest risk and mortality, and a high serum level of 56 had a 42% higher risk of dying than those with a serum level of 20. A similar study in the US (PloS One) found the lowest mortality among those with serum D levels of 20 – 40, and an Israeli study found the lowest mortality with levels of 20-36. Finally, a study by Bischoff-Ferrari found a high incidence of falls among people receiving 60,000 IU of vitamin D vs. those taking 20,000 IU. Based on all this, ConsumerLabs recommends maintaining vitamin D blood serum levels in the 20 – 30 ng/ml range, but not higher. This seems to make sense to me. I would love hear the NurtitionFacts experts opinions on these studies and the conclusion that too much vitamin D is not advisable.

    1. Interesting information, Scott. Correct me if I am wrong, I assume the studies you mentioned were done on people who were supplementing with vitamin D. I must wonder whether the negative consequences of high vitamin D levels stemmed from the vitamin being ingested as a supplement, as opposed to produced naturally.

      1. Yes, studies were all of individuals who supplemented. I have seen information from another source that you can’t get too much vitamin D from sunlight. There is some sort of natural mechanism that prevents it. But I can’t remember the source! :( If I do I will post it.

    2. The problem with the study in my opinion is that it uses once monthly bolus dosing. This surely spikes levels part of the month and may also increase the rate at which the vitamin metabolized. I wonder when the researchers timed the blood draws in relation to the bolus doses? While the increased vitamin levels would increase osteocalcin levels it might well be undercarboxylated if the subjects didn’t have a vitamin K2 level to match.
      If the osteocalcin is undercarboxylated, it won’t be doing its job of bone building.

  27. Similar Europe mortality rate. People living in the south have 50% or more sun throughout the year whereas people living in the north especially Scandinavian countries have the lowest rate yet the latter have the longest expectancy > 80 years whereas people in the south can barely reach 65/70.

  28. I also posted this in another video so sorry if some of you read this twice. It’s very important to me. And I try to reach a lot of you.

    Hello Dr. Greger & Team, hello NF community. I need your help.

    My 70 year old mother was recently diagnosed with breast cancer. She was shocked because she was always very positive that she would not get cancer. She is a very active person and you would not guess her age correctly if you see her. :)

    After all the routine checks her doctor made a biopsy and found out that it is an invasive carcinoma. They operated very quickly and removed 3 small tumors. Operation went by quickly and she is also recovering very well from the operation. Just minor pain and she should not lift heavy things.

    Now the doctor recommends chemotherapy and radiation. Furthermore she has a few friends, some doctors as well, who also had cancer and also recommend she should do chemotherapy and radiation. It’s a problem. I gave her several books to read, Overdiagnosed, China-Study, Whole, and several NF videos. She only speaks german and very little english so i can not give her the actual studies to read. I also started her on a WFPB diet with focus on cancer fighting food.

    I am afraid that all the talk about chemotherapy and radiation from her friends and doctors won’t let her make an objective decision.

    I will go with her to her next meeting with her doctor and try to find out if her doctor is open to a WFPB approach.

    It would be great if you can point me to studies that show that chemotherapy and radiation does more harm than good and that a WFPB diet with meditation and exercise is at the very last as effective in stopping cancer growth and spread.

    Thanks a lot for all your help.

  29. There are different types and ways to eat on a Plant based diet but I agree with you on the omega 6 to 3 ratio but not on the meat and fish sorry. Too much of fat for my own experience as my body thrives on a low fat/high carb diet. Most people I saw on this diet eat tons of nuts and seeds and avocados. For myself I eat mostly green leaves, fruits, whole grains and as main meat replacement only legumes. I avoid completely all vegetables with too much fat on it and avoid eating a lot of nuts. Been doing it for many years for an important reason (clean arteries). My wife she is a doctor and her family got a clinic with many expensive machines including a Wave Pulsating Analysis Machine. I did the test after many years on this diet and my arteries age show to be 22 years of age while I am 40. Was for them the first time ever to experience someone with such result. My wife she follows my same lifestyle but she eats once a week also a very few amount of meat and some sushi as she is Japanese. Her result on the WPA test was 42 years of age and she is 42. So not too bad but absolutely not my remarkable results that led the doctors asking me so many questions on my lifestyle for at least one hour as they wanted to learn what could have caused such a positive result. (for the curious people in here) together with my daily dinner made of legumes soup I use always a copious amount of Turmeric, black pepper, 2-3 ground table spoons of flaxseeds and 3-4 chopped walnuts. (of course also with a chopped red onion, 2 piece of chopped garlic and some other herbs). This is my dinner ritual. I do not eat any oil, any vegetable with fat, just 3-4 nuts daily and a lot of ground flaxseed in all my 3 daily meals. In the morning 5 days a week I eat whole cooked rolled oats and I mix in it Cinnamon verum, A lot of Cloves powder and ginger powder. Generally at lunch only 100% fruits smoothies made mostly with bananas, dates, berries and a lot of Kale or spinach whichever I find cheaper in a box. I still add cinnamon, cloves, ginger and raw 100% cacao powder in it. I feel an amazing energy all day long this way and I can support my cycling routine. If someone does not eat many nuts and fatty vegetables but use a lot of Flaxseed I think would be hard to get an imbalance omega6 to 3 ratio. I also supplement with Vit D, K, B12 and a plant based DHA. This worked well for me and I hope will continue to work in the future also. I will repeat the WPA test probably in couple of years time. My total cholesterol level from a blood test I had end of April was 116mg/dl, Triglycerides 62mg/dl, HDL 36mg/dl, LDL 42mg/dl. I do not think at all my body needs meat or fish as I feel very good and my general blood test was very good including my hormone test, Thyroid function, Iron Studies test, Serum Vitamin D 120nmol/L,Calcium 2.41nmol/L, Serum B12 assay 664 pmol/L higher then the all meat eaters he examined (by my doctor statement).

  30. From the journal *Aging*, last April: http://www.aging-us.com/article/9R5JsRe8k4Jq7uTXj/text

    The principal author, Dale Bredesen, a leading researcher in the area of dementia and cognitive decline, presents an interventional program called the MEND program. See http://www.alzheimersweekly.com/2014/10/25-ways-to-mend-memory.html This program calls for an anti-inflammatory diet. A WFPB diet definitely qualifies. But notice the recommendation for vitamin D levels between 50 and 100 ng/ml (not nmol/l). Keep in mind that this is evidence-based. We’re talking about real people who experienced real reversals in cognitive decline. I think it’s safe to say that just about no one is going to get vitamin D to those levels without supplementing, unless they spend a lot of time outdoors in near-tropical latitudes without a lot of clothing on. And note the recommendation for K2 to accompany the D. You could easily get this from eating natto, but if you can’t stand that stuff, as I can’t, it’s not hard to supplement. There are even supplements that combine the D+K2.

  31. I was taking 10000 iu of D daily and my storage and active D went over 100. Discovered I have a VDR genetic mutation which makes me convert at high levels. I stopped all supps and at 50.

    1. Early researchers on the topic in the 1940’s and 1950’s claimed they saw a huge range of individual response to the vitamin as I recall.

  32. But isn’t Vitamin D3 from animal sources??? So we should get Vitamin D2… Not supposed to be as well absorbed though.. Please someone, can you clarify? Thank you!!

    1. patricia Lambers: Most D3 comes from animal sources, but you can get vegan D3 also, usually from linchen I believe. While I’m not promoting the following as a special or good brand, I present the following to you as an example: https://www.amazon.com/MRM-Vegan-Vitamin-5000IU-Capsules/dp/B00CYA8HMW/ref=sr_1_2_a_it/161-7518659-9538702?ie=UTF8&qid=1478013910&sr=8-2&keywords=vegan+vitamin+d3
      .
      From my reading of the information on this site, I came to the conclusion that D2 works just as well also–when talking about amounts generally recommended for most people. But I’m not 100% sure I absorbed the information correctly. So, you would want to do more research if you are concerned about which type to take. Here are Dr. Greger’s overall optimum nutrition recommendations: http://nutritionfacts.org/2011/09/12/dr-gregers-2011-optimum-nutrition-recommendations/ These recommendations were updated in February and say: “daily recommendations for those in the Northern Hemisphere; D3 from animal or plant sources may be preferable to the D2 sourced from fungi” So, if you want to follow Dr. Greger’s recommendations, then do the D3.

      1. As I recall Hollis did research on the comparison fo D2 to D3. Conclusion was to use D2, it was best to use it daily as it has poor affinity with the binding protein in comparison to D3.
        Bolus dosing of D2 is a bad idea, even with D3 its dubious especially on a monthly basis, IMO.

  33. Would Vit D help the immune system of someone facing a barrage of mandatory vaccinations for employment reasons? I’ve also heard huge doses of Vit C would be beneficial. Any suggestions would be highly appreciated.

  34. Hi, I’ve seen a few videos that talk about supplementation necessary when on a whole plant food diet. Is there an article that summarizes the necessary / advisable supplements one would need if following the daily dozen regimen?

    Thanks
    Sterling

  35. So just what is the story on Vit-K2?
    Would someone at NutritionFacts.org kindlly step in and spill the beans?
    I have searched the site and find only reader comments.
    Does Dr. G have an opinion on the efficacy of K2 and calcium absorption?

    thanks, this is important to me.

    ed

    1. Hi Edward. I’m Crystal, a volunteer moderator and I’ll try my best to help you.

      Dr Greger answered a question What are the best sources of vitamin K? you might want to check it out. Vitamin K1 (phylloquinone) is found in plants and Vitamin K2 (menaquinone) in animal products.

      You might find these videos interesting Plant vs Cow Calcium and Calcium Absorption: Soy vs Cow Milk. Dr Greger talks about calcium absorption and vitamin K.

Leave a Reply

Your email address will not be published. Required fields are marked *

Pin It on Pinterest

Share This