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What’s the Best Ferritin Level to Lower Cancer Risk?

If cancer is indeed a so-called ferrotoxic disease, a consequence, in part, of iron toxicity, that would explain not only the dramatic drop in cancer rates after blood donations, but also why people with higher levels of iron in their blood have an increased risk of dying from cancer, why women who bleed into their ovaries are at high risk for ovarian cancer, and why those suffering from hemochromatosis (an iron overload disease) have up to 200 times the risk of cancer. There has even been a call to go back and look at some of the chemotherapy trials that kept taking blood from the chemo group to check for side effects. Perhaps just the iron removal from the blood draws accounted for some of the apparent chemo benefits.

Iron may be a double-edged sword, as I explore in my video Donating Blood to Prevent Cancer?. Iron deficiency causes anemia, whereas excessive iron may increase cancer risk, presumably by acting as a pro-oxidant and generating free radicals. Iron-deficiency anemia is a serious problem in the developing world. “In meat-eating countries, however, iron excess may be more of a problem than iron deficiency…Body iron stores accumulate insidiously with ageing due to the fact that intake exceeds loss,” and our body has no good way of getting rid of excess iron.

Ferritin is a blood test measure of our backup iron stores. As you can see at 1:31 in my video, the normal range is about 12 to 200 ng/mL—but just because it’s normal doesn’t mean it’s ideal. In the blood donor study discussed earlier, those who developed cancer had ferritin levels around 127.1 ng/mL. The average for men may be over a hundred.

This suggests that so-called normal, “ambient levels of iron stores may be noxious and constitute a ‘public’ problem that affects large segments of the population.” As such, “[t]here may be a need to redefine the normal range…based on associated disease risk” rather than following a bell curve. “Thus, iron deficiency may exist when ferritin levels decline to less than about 12 ng/mL, whereas ferrotoxic disease may occur with levels greater than about 50 ng/mL.”

Harvard recently looked at blood donations and colorectal cancer, and found no connection, but the range of ferritin levels the researchers looking at was roughly 100 to less than 200 ng/mL, as you can see at 2:28 in my video. What’s more, those were from individuals who reported giving blood 30 or more times. So, perhaps instead of draining our blood to reduce excess iron stores, why not prevent the iron overload in the first place? If we measure the iron stores of men who stay away from heme iron and, instead, get all of their iron from plants, their iron levels are right around where the cancer-free donor group came in, as you can see at 2:54 in my video. This may help explain why those eating plant-based diets tend to have less cancer and other diseases associated with iron overload. Indeed, they may also have less pre-diabetes, as well as have less diabetes.

For more on the blood donor study I discussed, see Donating Blood to Prevent Heart Disease?.

For more on diet and iron levels, see The Safety of Heme vs. Non-Heme Iron and Risk Associated with Iron Supplements.

Interested in other examples of normal lab values not being necessarily ideal? Check out:

Even though a plant-based diet may be preferable for personal disease risk, that doesn’t mean we shouldn’t all give blood. Join me in supporting the Red Cross.

In health,
Michael Greger, M.D.

PS: If you haven’t yet, you can subscribe to my free videos here and watch my live presentations:


Michael Greger M.D., FACLM

Michael Greger, M.D. FACLM, is a physician, New York Times bestselling author, and internationally recognized professional speaker on a number of important public health issues. Dr. Greger has lectured at the Conference on World Affairs, the National Institutes of Health, and the International Bird Flu Summit, testified before Congress, appeared on The Dr. Oz Show and The Colbert Report, and was invited as an expert witness in defense of Oprah Winfrey at the infamous "meat defamation" trial.

41 responses to “What’s the Best Ferritin Level to Lower Cancer Risk?

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  1. Can you please release a video about haemochromathosis? It would be of great help to inform about the Celtic curse condition. Thank you in advance

    1. In the meantime, I have learned a lot from

      I am vegan but am genetically predisposed to absorb too much iron and my ferritin has been over decades typically between 85 and 123, so this information is a concern. After two blood donations about 3 or 4 months apart last year, it dropped from 123 to 55 to 32! This is the best way to manage iron overload.

      I drink coffee or black tea and use some spices like oregano to help block iron absorption. Also it is important not to have a lot of vitamin C with meals as that radically increases absorption. But blood donations are the way to go.

  2. Some doctors say that those with Thalassemia may have many times higher than normal Ferritin levels to compensate for the deformities. Is that not true?

    1. @Norman Allen, I believe it is true; I must say I am one of the unfortunate person out there who was diagnosed with Thalassemia from being anemia all my life. I don’t understood why my ferritin level was from 964ng/ml up to 1338ng/ml in the seven months of every 3 months test period. The standard range: 22-291ng/ml. I did not know what to do, and my doctor couldn’t even tell me solution to help it bring it down. I was fed up and having all muscle tensions, and inflammations especially I love working out -I couldn’t do as much due to the pain, and the worst part was energy was very low.
      I was almost going to give up and just take some pain killers or some sleeping remedy just to get through my day to day activity. Then, one day I decided to make a change with my food intake. Plant-Based diet is my last resort, but miraculously it works.
      Changing my diet from carnivore’s to plant- based was difficult to manage, but it’s has been going on 7 months now for at least for 5 days of a week, I feel the dramatic difference with my energy, and recovery. I also feel that I can workout longer than I used to but the most amazing part was not having chronic inflammation and muscle tension in my body. I could say this from my experience. It’s almost time for me to get my ferritin count get again, so will keep it post.

        1. @spring03 I appreciate your support. I am religiously do my farmers market produce shopping three times a week. I make my food from scratch, and I feel that I have a better reward to myself when making, chopping, and cooking my food. I also own two of the famous books of Dr. Greger and I must say, I have learned a lot than I expected. God Bless

  3. Hello.
    I very much appreciate all the information on the website. We switched to plant based nutrition as of Jan 1st this year – mostly because of Dr Gregor! It’s been super, except for a bit of confusion about getting enough Omega 3 and B12.

    Interesting article about Iron.

    I understand there is a lot of iron in the organic cacao powder I put in my morning Omega 3 shake:
    -one banana
    -250 ml almond milk (or soy milk)
    -one Tbsp finely ground flax seeds
    -one Tbsp ground organic pure cocoa powder (no sugar)

    I’d love to know:
    a/ Is this is a healthy shake to be having every day?
    b/ Is this amount of flax a sufficient source of Omega 3 (i.e. can I count on my body making the EPA and DHA from the ALA in the flax? And if not, then how do I choose an algae-based EPA/DHA source that has no heavy metals?)
    c/ Should I cut out the cacao powder for any reason?
    d/ We take the Vegan Society “Veg One” multivitamin. We eat a great variety of fresh fruit and veg, but no meat or fish. Just want to know if this seems like enough supplementation to be in the safe range?

    The vitamin contains:

    Vitamin B2 (1.6mg – 114%)
    Vitamin B6 (2mg – 143%)
    Vitamin B12 (25 µg – 1,000%)
    Vitamin D3 (20µg – 400%)
    Folic Acid (200µg – 100%)
    Iodine (150µg – 100%)
    Selenium (60µg – 109%)

    Thanks very much.


    London, Tuesday, March 17th, 2020

    1. Dr. John McDougall has been advocating for a whole food plant based diet for four decades. All of our plant based doctors today stand on the shoulders of the great Dr. John McDougall. Go to his website and study the information he has on supplements. All the information is free. Better yet read his book “The Starch Solution”. (Or any of his other books for that matter.)

    2. With respect to algae based EPA/DHA, I think that there is only one manufacturer, but there many brands. This is a lab grown product and won’t have heavy metals. The problem with fish oil seems to be from heavy metals and then the distillation process they use to reduce heavy metals. Anyway stick with the algae grown. I use Nordic Naturals brand.

    3. Luce,

      There is a big reason there is a debate.

      The answer will depend on a lot of things.

      Do you eat a lot of greens?

      Do you eat nuts or use oils? If you do, supplementing prevents you from having the wrong Omega 3/Omega 6 ratio. Usually, the people who tell you to not supplement, tell you to eat flaxseeds, eat a whole lot of greens and don’t eat nuts or oils. The Adventists vegans doing better if they ate nuts is the logic to eat nuts and the side who says not to supplement throws out a study that Dr. Greger said was retracted, corrected and brought back and still showed a benefit. Dr. Greger is pro-supplementing based on MRI of brains of people who supplemented DHA versus those who didn’t – the brain structure was preserved in those who supplemented. Dr. Fuhrman (who sells DHA and is disregarded by many people) said that the original Whole Food Plant-Based movement that it was strokes and neurological diseases that those people had related to not supplementing and that the vast majority of vegans tested low. Only 9% tested high and 65% tested very low. He said that the original leaders of that old movement thought they were safe, but they got neurological diseases and when he tested his friends/mentors who got things like Parkinson’s their levels of DHA were non-existent.

      Do you know that your body converts ALA to DHA? (Often males and post-menopausal women don’t convert, but you only know if you test.)

      No matter what, find out your test results, don’t wing it. Your brain is at stake.

      As far as B12 goes, there were 14 studies where vegans didn’t supplement and they got high homocysteine and again, high-homocysteine is related to all kinds of health risks. So, you aren’t safe to keep not supplementing. If you have high levels, you can miss some doses, but eventually, you will likely get high homocysteine.

      1. Luce,

        I wrote that too complicated.

        65% of vegans test seriously low for DHA and not having enough DHA causes the brain to deteriorate faster. Only 9% tested optimal levels.

        You might be able to do it with diet, but you should get tested because some people can’t convert ALA to DHA at all and MOST vegans FAIL.

        As far as B12 goes, in 14 studies vegans who didn’t supplement got high Homocysteine levels.
        Higher homocysteine than the meat-eaters and when they gave them B12, they had lower Homocysteine than everybody else.

        That doesn’t mean you need to mega-dose.

        Dr. Greger will be having a B12 webinar soon.

        1. The people who succeed with diet alone are not “winging it” and I say that because so many people who are “winging it” are failing when tested.

          There is a trend right now of not supplementing – but if you look at the ones who are not supplementing B12, they will tell you that they have been supplementing for 20 years and have very high levels, so that affords them the opportunity to play around a bit, but if you do that, you need to test your MMA and Homocysteine.

      2. How do you test for this? Is there a profile to test for all the essential fats?

        Thank you for the information on B12 and homocysteine levels. I think that’s my problem my MMA and B 12 we’re fine I don’t supplement and will start because my homocysteine is elevated.

    4. Luce, first, welcome to the vegan club. This April will be 30 years since I’ve eaten meat, and I’m a healthy 75, almost 76, despite what appears to have been heavy exposure to Agent Orange in Vietnam.

      You made me curious as I also put a tablespoon of organic cacao powder in my pudding I put on my cereal. Cacao has one of the highest amounts of iron of plants, and it’s higher than most meats, but it is what is known as non-heme iron, which is what all plant food iron is, versus heme iron in meats. The difference is we need to take Vitamin C to absorb non-heme iron. As a result, I took my last Vitamin C supplement this morning, because I don’t need all that iron in cacao being absorbed by my body.

      As for the ground flax seed, I’ve been doing a heaping tablespoon (probably 4 tsp) of it in my morning pudding every day for many, many years.


    5. It looks like most of your questions have been answered, but I’d just encourage you to check out this website: if you haven’t yet. Also I’d ask if you are having that smoothie as your breakfast daily or is it a treat. If it’s your breakfast, you may want to consider having smoothies only 2 or 3 times a week and having an alternate more fiber-filled breakfast (think oatmeal or berries, apple, orange–all that require chewing!) If your smoothie is a treat, perhaps having it more an an occasional treat, rather than daily, and again replace with more whole and varied fruits or veggies. Bananas are good, but remember you need to get a rich variety of nutrients.
      Best of health as you enjoy your smoothies and lots of other plant-based treats. Joan-NurseEducator

  4. Is there information on an ideal range for ferritin? Mine is below normal (ferritin at 8) and doctors seem concerned because I’m in the anemic range. I’m not sure that I should be worried about increasing my levels of iron, RBC’s and ferritin or if below average is ok.

    I am glad to know that my low levels decrease my risk for cancer! Thanks for the information.

    1. Cheryl, I get a copy of my blood test results because the show the reference ranges right beside your result.
      My results often show iron deficiency (i have been eating wfpb many years). Recently it came in at 6 so I am on iron supplements at the moment. If I retest and it comes in above 15 I will stop the supplements probably. 25 is my goal.

    2. Cheryl, You mentioned you have been told you are in the anemic range. Is this based on just the level of ferritin or were other tests ? 8 certainly sounds low, but if you review this video, a mention is made that vegans with a level of 72 for ferritin seemed to have the best outcome- not suffering effects of low iron yet not increased risk of cancer. Still 8 is a long way from 72, so do continue working with your doctor, of course. That doesn’t mean you need to start eating meat with it’s heme iron, but it’s possible a temporary treatment plans may be needed. You did not mention if you are having symptoms, but those certainly should be reviewed as well as lab results. Best of health to you while you get resolution.

  5. Hopefully this will be helpful iron-related info to other plant-based eaters, as I’ve recently got back some test results:

    I, too, as a long time plant eater (who “gets all of [my] iron from plants”–for about 15 years I would guess) have been told by regular docs that my iron is on the low side. I recently got a number of tests. Low, yes, but the doc was not concerned. The Quest lab ferritin “reference range” is different from what the article above suggests–it’s wider. I don’t suffer from anemia and my energy is just fine (49 yo male, commutes by bike, yoga, surfs, etc.), so I think I’m all good–which, based on the article, seems to suggest there’s a positive to being lower rather than higher.

    My iron-related labs:

    Ferritin:16 L (not sure what the L is next to the results, which were in ng/ml)
    -Stated reference range: 38-380 ng/ml
    -this was the only iron-related test that was “out of range”
    Total iron: 87 mcg/dL
    -Stated reference range: 50-180
    Iron binding capacity: 353 mcg/dL (calc)
    -Stated reference range: 250-425
    % Saturation: 25% (calc)
    -Stated reference range: 20-48

  6. ‪Artemisinin has been found to bond to heme and with anti-cancer and anti-malarial effects. I’ve read research papers suggesting it can “ride” the heme into the heme-hungry cancer cells and unpack like a Trojan horse!


    1. Nikki,

      That has to be balanced with the reality that not having the heme is way more anti-cancer than using a supplement that binds to the heme.

  7. I wonder why the Fe in hemoglobin is so different than Fe in plants. Is it the Fe++ reduced from in plants or the Fe+++ oxidized form in blood. I don’t get it why heme blood is so pro-oxidant from plant iron, since it is all just Fe iron. Is there an explanation?

  8. Interesting topic and one I’d like to investigate further. I was on a WFPB diet for years and suffered from LOW iron/ferritin levels. I tried to bring up my levels with plants for 2years but no luck. When I had to do supplements and my levels still didn’t rise, that’s when they found out I had colon cancer. After they removed the tumor and I did chemo, my levels started to go back up. Hmmmm….

  9. I donate blood every 56 days and at one point my iron was too low to donate and the Red Cross recommends in their literature for frequent donors to take a supplement, so I take a Vitron-C every other day (my Drs. suggestion). Is this a good thing or bad? I want to be able to continue donating, but can’t if my iron is too low, but I certainly don’t want to be increasing my cancer risk.

    1. Good for you, Ellen for being a regular blood donor. That’s especially important now. While I can’t speak specifically on the specific iron supplement you are taking, there are concerns about supplements in general and questions on whether a ferrous or ferric formulation or daily versus less frequent dosing is better (It’s good you are taking the Vitron-C only every other day. Wonder if you could take it even less often if you continue with it?
      Here are two research articles, if you want to get into this more deeply: Iron supplements taken one, two or three times a week for preventing anaemia, and its consequences in menstruating women Ferrous versus Ferric Oral Iron Formulations for the Treatment of Iron Deficiency: A Clinical Overview
      You have not indicated if you are eating a whole food plant based diet and making efforts to ensure you’re eating and absorbing maximum iron. Also you said you took the Vitron-C at your doctor’s suggestion so you may want to revisit that issue in the light of research showing a potential CA risk with supplements. Finally even if you have done your best to get iron from plant-based foods, your doctor still suggests Vitron-C, I’d be questioning in manufacturer to feel comfortable this is a supplement that has been tested for quality and contaminants. See if the company has a good reputation and can answer your question. I don’t want you to give up on blood donating, but I encourage you to consider how you might bring up that iron without daily Vitron.

  10. It’s estimated that 85–90% of total iron intake comes from the non-heme form, while 10–15% comes from the heme form. This statement is sourced from PubMed. Hence, this write-up is deceptive.

  11. What do we know about absorption of iron from using cast iron cookware? I thought cooking in iron pand was discouraged since this creates an oxidative stress that you would want to avoid (information from reading Dr. Fuhrman’s books (vegan) but seems like it is the best option for cooking since aluminum and non-stick coatings are all probably more toxic than iron.

  12. I’m wondering if supplementation with iron bisglycinate chelate (non-heme, solgar brand 25 mg) is still harmful to take? My dr wanted me to supplement with iron because my hemoglobin dropped from 13.1 Last year to 11.9. My most recent blood draw was after 2 months on WFPB diet. I’m sticking to the way of eating religiously because my cholesterol dropped to 149 down from 198 and I feel amazingly healthy to boot. To be fair I’ve always suffered from heavy menstruation which has only insignificantly improved on this diet (5 months at this point). I’ve even considered hysterectomy to resolve the issue but I’m concerned that the cure could be worse than the problem. I eat a lot of iron rich plant based foods along with citrus to increase absorption. I’m taking the iron supplement for now at least until I see the results of the next draw.

  13. Hello, Dr. Greger !

    Thank you for the great article.

    I am doing daily dozen since October 2017.

    I have done a blood-work and it seems good (TC=120, LDL=63, Lp(a)=8, homo-cysteine=7,2, folic acid=9,4 ).

    However, I would like your opinion for my ferritin which is very low at 9,9, below the minimum limit of 12.

    – I eat 1 pepper at all 3 meals,
    – I never drink tea with the meals, and
    – according to cronometer, I eat plenty iron.

    So, I am really clueless why I have so low ferritin.

    Can you give me a few ideas on how to improve iron ?

    Of course, I will ask my doctor but he is not doing WFPD, and I would like the thoughts of similar-minded people.

    Thank you for your time

    Best regards

  14. Congratulations on being so consistent on eating the Daily Dozen! While it certainly seems your lab values are good and I’m sure you don’t have any of these symptoms that might indicate low ferritin level: Pale or yellow skin.Extreme tiredness and dizziness.Heavy menstrual cycles.Bleeding in your digestive tract.Blood in your stool.Shortness of breath or chest pain, especially with activity.Brittle nails or loss of hair.Pounding or “whooshing” sound in your ears (Source:
    When I searched for reasons for low ferritin, I found one study that indicated extra weight could be a factor, but you didn’t indicate that. (You could check out this article:

    I found another scholarly article about low ferratin and treatment approaches which you might want to read before you see your doctor.
    Dietary strategies for improving iron status: balancing safety and efficacy

    Meanwhile you could look over this less scholarly article which did have a few practical tips, most of which you are doing.
    “There are many good sources of non-heme iron. Dark leafy greens and dried beans are among the best vegetarian sources of iron. Many breakfast cereals and bread products are fortified with iron, so make sure you’re eating plenty of those, especially whole-grain foods,,,.
    In addition, several types of foods can reduce the amount of non-heme iron that the body absorbs. For example, the tannins in coffee and tea, dairy products, fiber, eggs, and some types of chocolate can inhibit the absorption of non-heme iron. The good news is that vitamin C helps to markedly increase the absorption of non-heme iron. For instance, drinking a glass of orange juice with your dinner can increase non-heme iron absorption up to six-fold!”
    You did not mention taking in orange juice (not usually promoted on this site, but it could improve iron absorption, so you could try a small daily glassful for a week or so to see if that helps, along with all those dark leafy greens you are already eating….

  15. Has the team ever considered preparing a one-pager on the “optimal” blood-test levels we should be looking for, rather than the ranges listed as “normal” when we receive results from the lab?

    I would find such a reference to be super helpful… sort of like the printable one-pager of the Daily Dozen, and the brief list of recommended supplements.

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