Risk Associated with Iron Supplements

Risk Associated with Iron Supplements
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Iron is a double-edged sword. If we don’t absorb enough, we risk anemia; but if absorb too much, we may increase our risk of cancer, heart disease, and a number of inflammatory conditions. Because the human body has no mechanism to rid itself of excess iron, one should choose plant-based (non-heme) sources, over which our body has some control.


Iron is a double-edged sword. If we don’t absorb enough, we risk anemia. But if we absorb too much, we may be increasing our risk of colorectal cancer, heart disease, infection, neurodegenerative disorders, and inflammatory conditions. Other conditions that have been associated with high iron intake include Alzheimer’s, Parkinson’s, arthritis, and diabetes.

Because the human body has no mechanism to rid itself of excess iron, we evolved to tightly regulate the absorption of iron. If our iron stores are low, our intestines boost the absorption of iron, and if our iron stores are topped off, our intestines block the absorption of iron to maintain us in that sweet spot. But this only works with the primary source of iron in the human diet—the iron found in plant foods. Our digestive system cannot regulate the iron in ingested blood—heme iron. The iron in animal foods can just zip right through our intestinal barrier—even if we already have too much in our system; we have no control over it.

In fact, some guess that iron overload may be a reason that meat consumption has been tied to breast cancer risk. Iron is a pro-oxidant, and can induce oxidative stress, and DNA damage. “A high intake of iron in developed societies may, over time, lead to a physiologic state of iron overload in postmenopausal women, who are no longer losing blood every month. Iron overload favors the production of free radicals, fat oxidation, DNA damage, and may contribute to breast [cancer development] carcinogenesis independently or by potentiating the effects of [other carcinogens].”

Only people with a confirmed diagnosis of iron deficiency anemia should consider supplementing their iron intake, and even then, it can be risky. A recent study found that a significant increase in oxidative stress happened within the bodies of women on iron supplements.

And so, before going on iron supplements, I would suggest talking to your physician about first trying to treat it through diet alone—by eating lots of healthy iron-rich foods, like chickpeas and pumpkin seeds, while consuming vitamin C-rich foods at the same meal, such as citrus, tropical fruits, broccoli, bell peppers, which improve plant iron absorption, while at the same time avoiding drinking tea and coffee with your meals, which can impair iron absorption.

Since organic acids like vitamin C can boost iron absorption, the Coca Cola company commissioned a study to see if drinking Coke would do the same thing. And the answer is: no.

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

Please consider volunteering to help out on the site.

Images thanks to Søren Niedziella and Thirteen Of Clubs via flickr. Images have been modified.

Iron is a double-edged sword. If we don’t absorb enough, we risk anemia. But if we absorb too much, we may be increasing our risk of colorectal cancer, heart disease, infection, neurodegenerative disorders, and inflammatory conditions. Other conditions that have been associated with high iron intake include Alzheimer’s, Parkinson’s, arthritis, and diabetes.

Because the human body has no mechanism to rid itself of excess iron, we evolved to tightly regulate the absorption of iron. If our iron stores are low, our intestines boost the absorption of iron, and if our iron stores are topped off, our intestines block the absorption of iron to maintain us in that sweet spot. But this only works with the primary source of iron in the human diet—the iron found in plant foods. Our digestive system cannot regulate the iron in ingested blood—heme iron. The iron in animal foods can just zip right through our intestinal barrier—even if we already have too much in our system; we have no control over it.

In fact, some guess that iron overload may be a reason that meat consumption has been tied to breast cancer risk. Iron is a pro-oxidant, and can induce oxidative stress, and DNA damage. “A high intake of iron in developed societies may, over time, lead to a physiologic state of iron overload in postmenopausal women, who are no longer losing blood every month. Iron overload favors the production of free radicals, fat oxidation, DNA damage, and may contribute to breast [cancer development] carcinogenesis independently or by potentiating the effects of [other carcinogens].”

Only people with a confirmed diagnosis of iron deficiency anemia should consider supplementing their iron intake, and even then, it can be risky. A recent study found that a significant increase in oxidative stress happened within the bodies of women on iron supplements.

And so, before going on iron supplements, I would suggest talking to your physician about first trying to treat it through diet alone—by eating lots of healthy iron-rich foods, like chickpeas and pumpkin seeds, while consuming vitamin C-rich foods at the same meal, such as citrus, tropical fruits, broccoli, bell peppers, which improve plant iron absorption, while at the same time avoiding drinking tea and coffee with your meals, which can impair iron absorption.

Since organic acids like vitamin C can boost iron absorption, the Coca Cola company commissioned a study to see if drinking Coke would do the same thing. And the answer is: no.

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

Please consider volunteering to help out on the site.

Images thanks to Søren Niedziella and Thirteen Of Clubs via flickr. Images have been modified.

139 responses to “Risk Associated with Iron Supplements

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    1. You are becoming the physicians physician.

      This is extremely helpful for anybody in the healthcare industry that deals with iron abnormalities.  A must watch.

      It is fascinating to me that our bodies cannot regulate animal sources of iron but it can plant sources.  I was never taught that in medical school (Am I surprised? No!). 

      Now I may be incorrect but that means to me that we have evolved eating plants and not animals; for if we had been eating animals throughout time, our bodies would have surely created a regulatory mechanism for absorption of animal based sources of iron. 

      I have never tried to treat IDA (Iron Deficiency Anemia) with a plant based diet.  But come to think about it all my patients that are on a plant based diet don’t have IDA.  Interesting!

        1. OK Doctors. I think this topic isn’t so black and white. I wish it was. 

          There really are some people who tend to be anemic–me for one. Northerns European Grandfather/Grandmother the cause? 

          Either way, as a serious runner I can’t stand that feeling of heavy legs while out on a 10 mile run. We don’t know  whether runners tend to be anemic due to sweating or the red blood cells getting beat up in our feet (a couple of theories). I do all the right things–I eat a ton of greens, a ton of beans, pistachio nuts and I include vitamin C foods. And still I am on the low side. (Ferritin levels hover around 20 if no supplement taken.) Even when I take a supplement I am just barely normal. So in cases like my own, one pill a day (taken with Vit. C)  can’t be too much of a concern. Obviously I must have some kind of absorption problem. “Toxins” suggested garlic may help. So one more addition to my morning smoothy! 

          1. Gale – sorry – I am just an enthusiastic plantstrong guy….

            Did you have the same problem when you ate meat (if ever)?

            I am from Northern Europe – no problem with hgb

              1.  I’m another runner on plant-based diet, also tending toward anemia– even though I’ve been taking iron supplements twice a day for a couple years. I’ve had AIDS for decades, too– so I’m not typical of the general population. I also don’t get to indulge in the sort of plant-strong pride that would let me think I can run this body w/o medicine. I’ve been thinking I need to boost my iron supplementation (Iron sulphate) again– but am a little unhappy about this video’s report of increased oxidative stress apparently resulting from iron supplementation. Maybe it’s back to pumpkin seeds, which I’d cut out owing to their poor omega3/omega 6 fatty acid ratio and the general Esselstyn dietary recommendation to limit nuts and seeds…. (chickpeas are also have a high omega 6 level, compared to other beans).
                I do include vitamin C rich foods at all meals, including those at which I take the iron pills.

                Gale seems so right to me that this topic’s not simple.

                1.  Lebepotter:  I can’t address the main point of your post, but I did want to respond to: “Maybe it’s back to pumpkin seeds, which I’d cut out owing to…”

                  I believe that there are several videos on this site concerning nuts which list studies which point to positive benefits of eating nuts and seeds.  I’m familiar with Dr. Esselstyn’s book and really liked it, but I wonder if this particular recommendation of his is still valid. 

                  I saw from the table of contents that Dr. Greger will be addressing nuts once again in volume 10/upcoming videos.  I do not yet know the content of those videos, but perhaps all of these videos will put your mind at rest concerning the consumption of nuts.  Maybe?

                  Good luck in whatever you decide to do.

                  1.  Thea, thanks so much for your thoughtful and exquisitely tactful reply! I have noted Dr. Greger’s consistent nut endorsements. Those help keep me eating a few walnuts– which even Dr. Esselstyn calls okay for patients w/o heart disease. Quite low levels of nut consumption seem to be sufficient to provide the benefits. Maybe that’s the sweet spot. Pumpkin seeds are, of course, not nuts, so who knows where they fit in? They haven’t, on their own, been enough to replete my iron stores in the past. But I’ve just been reading around on iron supplementation and oxidative stress and not at all liking what I see: “Iron supplements: the quick fix with long-term consequences” is a representative title, though that paper’s particular target is combined supplementation with (non-food) iron and (non-food) vitamin C. I’ll be watching for Dr. Greger’s upcoming items on nuts, and listening with mind open. Thanks, thanks again.

                    1. Lebepotter:  You sure do your homework.  I’m impressed.  I admire people who take responsibility for their health *and* go about it in a thoughtful and open-minded manner.  (I also admire people who run.  I’m hopeless…)  Thanks for taking my comments in the spirit in which they were intended.  :-)

                      I had to mention: the walnut dressing from Dr. Esselstyn’s book has become one of my parent’s favorites.  They put it over all sorts of things.

                    2. Thea, Yes! that Esselstyn  walnut dressing is delicious . Glad your parents like it and use it. Good w chopped scallions in place of all or part of the garlic, too., too. ons ins using is  is

                2.  I don’t run but have had lots of trouble with low iron for decades whether eating meat or not. Floridix is a non-heme iron suppliment from 100% plant sources. I take it off and on as need arises.

                3. If I didn’t eat nuts and seeds and avocado I would be too skinny. I think the idea is that processed foods have high levels of omega 6. Therefore the average SAD is high in omega 6. If you don’t eat that crap I think you are ok adding nuts and seeds. There are plenty of videos by Dr. Greger under topics regarding nuts and seeds. (or google)

                  FYI I just read the best books written by athletes (runners) who are also vegans. Eat and Run by Scott Jurek and Finding Ultra by Rich Roll.

                    1. The SAD is high in refined vegetable oils primarily from soybean oil used in packaged crackers, cookies, sweets, snacks. Therefore Americans get too much omega 6 and not enough omega 3. Does that clarify it for ya?

          2. “Hereditary hemochromatosis is the most common inherited single-gene disorder in people of northern European descent.”
            “Secondary iron overload should be suspected in patients with chronic anemia”

            1. Hi jhnycmitly, (mouth full)

              Man I just came back from the beach working on my vitamin D. What a beautiful day. OK explain that second comment. 

              I am very interested. 


          3. Gale,

            I found the articles below to be helpful for starting the process of improving my iron levels. I used to jog, but had to switch to powerlifting and resistance training (love it!) because the drain on my iron from jogging led to serious Restless Leg Syndrome, profuse hair loss, and the feeling of running into a wall of water after jogging for one block after a month of consistent jogging. I have never had anemia, am a long-time pescatarian, eat my veggies, and have chronic iron deficiency without anemia (normal hemoglobin, borderline ferritin) that I treat with ferrous bisglycinate and Vitamin C. I have no Northern European ancestry. I still have occasional issues, and had them even before becoming physically active, but seem to be gradually improving after starting Vitamin A supplementation several months ago at the maximum safe dosage of 10,000 IU/day.


            Applicable for some women of childbearing age:



          4. I have the same issue. I am a female runner, so lack of iron is even more prevalent. Even with daily liquid iron supplement, I am still testing near borderline deficiency. Is the supplement soothing I should still be concerned about?

      1. I actually have successfully treated my own IDA with a plant based diet. I’m a nutrition student and a vegan, and so after some particularly strapped-for-cash months spent living off of bread, rice and potatoes, my iron levels plummeted. I wrote myself up a nutrition plan and shortly after my iron has returned to normal. I also wrote up a nutrition plan for a friend whose iron levels had dropped not quite to the extent of anemia, and her levels returned to normal pretty much straight away.

          1. Hi Michelle. It included plenty of kale, parsely, rocket (arugula), broccoli, red split lentils, chickpeas, black beans, nuts, pepitas and sunflower seeds as well as quinoa and brown rice. Recipes like kale and chickpea salad with tahini lime dressing, tabouleh, masoor dahl, chickpea curry, green smoothies, stir fried vegetables, black beans and tempeh/tofu, lentil & black bean patties with steamed veggies and salad.

            1. I also avoided tea, coffee, wine, spinach and silverbeet (chard) due to their iron inhibiting natures/poor iron bioavailability.

      2. My wife had her 1st checkup yesterday since she’s been in the United States (she’s from the Philippines). Her doctor was quick to write a prescription for iron without mentioning anything about nutrition. We would like to normalize it through nutrition if possible. Her Hemoglobin is 9.7, mcv 74.3, mch 21.9, mchc 29.5, red cell distribution 15.4, ferritin 3.6, iron 18, tibc 490, fe saturation 4%.

        She has been low in iron as far back as she can remember but still feels fine. Since the only other medical professional available to us is her primary doctor, I was hoping for guidance in this group as to… should she go ahead and take the medication? Either way, we have researched what foods she needs to get more of for both iron and vitiman c and she plans to diligently improve her stats. Any help would be greatly appreciated… Thanks very much!

  1. In the sources cited, I could not find support for the claim “our digestive system cannot regulate the iron in ingested blood…” 

    I read the article “Mechanisms of Heme Iron Absorption” by West and Oates and could not find support for this claim.

    Perhaps someone can point out where this claim is specifically made… If anything, it seems to me that all of the cited articles are recommending heme sources (i.e. meat sources) of iron to prevent anemia.

    1.  BPCveg:  Really great question.  Thanks for doing this research.  I hope someone answers your question, because I am interested too.  I often repeat information I learn from this site.  I want to be able to back it up anything I say.  Otherwise if people can say, “prove it” and I can’t to any one thing, then they think that everything I say is of questionable value.  (It is my experience that “throwing the baby out with the bathwater” is human nature.)

        1.  Thanks so much for taking the time to answer this question!!  I feel much better when I know these kinds of questions can be answered.  Your help is much appreciated.

          1. No it wasn’t removed it is below because of this thread.  Just look for responses to BPC from me.  My response wasn’t anything special ;-(

    2. BPCveg,
      Just a quick response.  I just scanned the “Mechanisms of Heme Iron Absorption”.   The following statement is from the Cartoon caption in the article:

      “Any iron released from heme inside the enterocyte, regardless of the mode of uptake, ultimately joins the labile iron pool and is transferred to the  bloodstream by FPN1 in the same fashion as non-heme iron.”

      This is what Dr. Greger mentioned in his video.  Mouth, to gut, to iron pool.  Our bodies cannot regulate the iron absorbed from animals.

      1. Not so fast, HemoDynamic.

         The sentence that you have cited relates to transport of iron after it is absorbed and does not distinguish between heme (meat-based) and non-heme (plant based) iron! I don’t think it is relevant.

        I think that the article is arguing the exact opposite of what Dr. Greger is claiming.

        Please note that not all heme (i.e. meat-based) iron is absorbed, as explained on page 2, paragraph 3: 

        “up to 19% of an equivalent dose of heme was absorbed[36]. This strongly suggests that heme uptake is a facilitated process, as opposed to simple diffusion. ”

        –> read that again, heme uptake is a FACILITATED process — i.e. it is regulated!

        Furthermore on page. 2, paragraph 2 the author’s state:

        “…the absorption of heme iron cannot upregulate to the same extent as non-heme iron during iron deficiency[14,15,21-25]. This is possibly due to rate limitations at the step of heme catabolism”

        Moreover on page 5, paragraph 2 the author’s state:

        “…the ability to upregulate heme iron absorption is limited compared to non-heme iron[14,15,21-25], and heme splitting is speculated to be rate limiting[67]. ”

        –> clearly even the rate at which meat iron is digested is regulated!

        Overall the authors of this paper very clearly argue in favour of consuming heme iron (i.e. meat-based iron), as they state on page 1,
        paragraph 2-3:

         ” Currently, the importance of heme iron in the diet cannot
        be underestimated. Studies estimate that in Western societies, iron derived
        from heme sources such as myoglobin and hemoglobin make up two thirds of the
        average person’s total iron stores despite only constituting one-third of the
        iron that is actually ingested[4-6]. This likely explains why vegetarians are
        more prone to iron deficiency than those who regularly consume red meat[7]. The
        relative importance of dietary heme is attributable to its high
        bioavailability compared with non-heme iron in the predominantly alkaline
        conditions found in the lumen of the small intestine. ”

        I fail to see the connection that Dr. Greger is trying to make and do not understand why he selected this article.

        I hope that others will be encouraged by my comment to read this article and try to interpret it for themselves.

        1. BPC,
          I’m not disagreeing with you. And you make a good point that there is some regulation.
          But I’m trying to figure out exactly what Dr. Greger is talking about.  And after watching the video again, he specifically points out the mechanism on the left side of the cartoon in the article showing that “Intact heme may be transported across the basolateral membrane (going straight into the blood) by FLVCR where it binds circulating hemopexin.” 

          And maybe there is more to this that he understands. 

           It is clear that our bodies uptake more Heme iron than Non-Heme Iron that’s why “myoglobin and hemoglobin make up two thirds of the average person’s total iron stores despite only constituting one-third of the iron that is actually ingested[4-6].”
          And if this is the case does this happen because there is less regulation of Heme iron compared to non-heme iron or is Heme-iron a preferred source by the body?

          1. Hi HemoDynamic,

            Thanks for your reply. I think the article in question was arguing that heme iron is better absorbed than the non-heme iron. Apparently both types of iron undergo sufficient regulation in healthy subjects to prevent iron overload.

            For more details, please see articles provided by Jans Louis, below, most importantly:


        2.  BPCveg: I think the confusion arises because Dr Greger is summarising a complicated process in a 2minute video. The sentence you quote from the article that “the ability to upregulate heme iron absorbtion is limited compared to non-heme iron” is consistent with what Dr Greger is saying, because the flip side of that statement is that the ability to downregulate heme iron absorbtion is also limited. Experiements have shown that absorption of non-heme iron is highly sensitive to how deficient the individual is and also to how much iron is in the meal (absorption of non-heme iron goes down with a higher amount of iron in the meal) but heme iron absorption tends to be much less sensitive to these factors. So if you eat a lot of red meat and have quite high iron stores, that is a problem because you will just keep absorbing the heme iron regardless. However, even though non-heme iron absorption is more sensitive to the iron status of individuals, it is still much more poorly absorbed overall relative to heme iron, which is why the authors of the article (and most dieticians) recommend heme iron because it is better able to prevent anemia. 

          For the person who is worried about chickpeas and omega-6 fatty acids, lentils are an even better source of non-heme iron. But really that concern over omega-6 is misplaced. As long as you avoid high omega-6 oils, the consumption of nuts and seeds will not be a problem and they have been shown so consistently to have positive health effects. Just throw in some flax seeds to balance things out.

          1. Hi Kate,

            Ok. As I understand it we have a system that is great at regulating non-heme iron or heme iron. (when ferritin levels are around 60 the uptake stops) However with some people their regulatory system doesn’t work properly. They either absorb too much iron which is stored in different organs (damaging) or not enough is absorbed and then tend towards anemia.

            I think the main point Dr. Greger is trying to make is that taking iron supplements can cause oxidative stress and should be done only as a last resort.

            I couldn’t find any research articles that stated that the absorption of heme iron was not regulated as well. It appears we have an amazing system if it is working properly.

  2. It is possible that the oxidative effects associated with a higher intake of meat are increased when the meat source itself has been fattened on a corn/grain-based diet high in Omega 6 rather than a natural grass based diet higher in Omega 3s, and has less to do with excess non-heme iron than excess commercially-raised meat.

  3. Just for everybody’s information concerning the absorption of heme iron.
    http://www.ncbi.nlm.nih.gov/pubmed/9756117 analyses also demonstrated an effective control of iron absorption preventing development of iron overload in otherwise healthy subjects even if the diet is fortified with iron and even if meat intake is high.
    The powerful control of iron absorption implies that dietary iron overload cannot develop in normal subjects, even with diets having high iron content or high bioavailabilityhttp://www.ncbi.nlm.nih.gov/pubmed/9250114Iron absorption from the whole diet, which contained a highly bioavailable form of iron, was measured for 5 d in 31 health men, including 12 blood donors. Nonheme iron in all meals was labeled with an extrinsic, inorganic radioiron tracer added in amounts to ensure uniform specific activity in all meals. Heme iron was labeled similarly by using hemoglobin biosynthetically labeled with another radioiron tracer. There was a good inverse relation between total absorption and concentration of serum ferritin up to approximately 60 micrograms/L. In subjects with serum ferritin > 60 micrograms/L there was no relation to iron absorption. At this serum ferritin concentration, absorption decreased to a level just sufficient to cover basal iron losses, implying that at a serum ferritin concentration > or = 60 micrograms/L no further accumulation of iron stores will occur by dietary iron absorption. The findings thus suggest that in normal subjects there is no risk of developing iron overload by iron absorption from the diet even if the diet is fortified. Similar findings were made previously in two studies in women, both of which indicated an effective control of absorption. At the same serum ferritin concentration the absorption per kilogram body weight was the same in men and women served identical diets with a high iron bioavailability. These new observations strongly suggest that translation of serum ferritin concentration into amounts of stored iron should be made with caution and that in subjects with high serum ferritin concentrations, other causes than increased iron stores should be considered. There was effective control of both heme- and nonheme-iron absorption but their relations to iron status were different.

  4.  Dr. Greger,
    I would very much like to get a definitive (?) word about the absorption of non-heme iron ins omnivorous vs. vegetarians. The only clear statement I have found so far is in an article by C. Kies and L. Mc Endree, titled “Vegetarianism and the Bioavailability of Iron” published in 1982 by ACS (American Chemical Society) in the proceedings of the symposium “Bioavailabilty of Iron”, ed. by C. Kies, ISBN-10: 0841207461, ISBN-13: 978-0841207462. There, I found the statement that vegetarians absorb non-heme iron more efficiently then flesh eaters. It looks like our body boosts the absorption of non-heme iron when it cannot rely on heme iron, while if the latter is present, then it becomes “lazy” at non-heme iron.
    Are you aware of any later studies on this subject?

  5. jhnycmltly,

    Thanks for the abstract, though preferably it would be a peer-reviewed journal article, which is typically a more rigorously performed study.

    I think that the conclusion of this abstract, namely, “unlike nonheme iron, heme iron absorption is not substantially reduced as iron stores increase”, seems at first glance to be consistent with Dr. Greger’s message. However, they do not associate this reduced absorption with iron overload, as implied by Dr. Greger.

    In fact, the peer reviewed articles sent by Jans argue the opposite that:

    “… in normal subjects there is no risk of developing iron overload by iron absorption from the diet even if the diet is fortified.”

    I am still unconvinced that meat-eaters are prone to iron-overload.

    1. Quote: they do not provide evidence that meat consumption leads to iron overload,

      Answer: The body has no way to excrete the iron once it is absorbed.
      “Iron differs from other minerals because iron balance in the human body is regulated by absorption only because there is no physiologic mechanism for excretion”
      Heme iron , as evidenced , is absorbed all the time and you do not believe , “unconvinced” , that heme-iron leads to iron excess.
      “unlike nonheme iron, heme iron absorption is not substantially reduced as iron stores increase”
      You should maybe stay out of medicine.

    1. A curious thing about that study. Other researchers went back years later and found those people who DID have the highest iron stores ? they NOW had diabetes.
      “Prevalence of iron load highest in Uummannaq (men, 32.1%; women, 21.1%).”
      “The prevalence of diabetes in Unmmannaq was higher than that in the towns of Nuuk and Qasigiannguit”


      Which means , “the dietary intake of haem iron” , predicted the development of diabetes because the FIRST researchers explained the high iron due to meat eating / haem iron.

  6. Good find, Carlos.

    Just read the full article, available freely: http://hal.archives-ouvertes.fr/docs/00/59/29/66/PDF/Corpet-meat-cancer-veg-safer-Meat-Sci-2011-Author-version-2011.pdf

    The conclusion made me chuckle:

    ” Our experimental studies in rats provide direct evidence that red meat and processed meat can increase colon carcinogenesis. They also strongly support the hypothesis that heme iron is the major cause of cancer promotion by red meat. Based on works by other researchers, our results add some evidence to two pathways linking dietary heme iron and cancer promotion. Lastly, we are suggesting several ways to prevent the toxic effect of meat, either by increasing the calcium load of the meal, by changing the meat processing, or by choosing new additives. Full demonstration of mechanisms and of chemopreventive substances has not yet been given, but we expect that these studies will lead to a reduction of the risk of colorectal cancer without losing the nutritional benefit and the pleasure of eating meat.”

    I guess we shouldn’t be surprised by the spin they add in the final sentence given the journal’s title. ;)

  7. Help!
    Have come accross a few people who’ve had problems with iron absorption when adopting a vegan diet…?!
    One said it was because of O type blood…is this possible?
    If blood type has anything to do with it, what can be done?

    Thank you immensely for this awesome and excellent site – we love you Dr. Greger!

  8. I understand this is not the forum for a medical diagnosis so I’m just sharing what I was told after various blood tests and “events.”  I’ve had intestinal bleeding four times in the past four years.  Of course, after the bleeding, I became anemic (after two “events”, I needed a blood transfusion).  The follow-up blood tests revealed that my body does not absorb nor store iron well and I was told to take “chronic iron” as my gastroenterologist put.  (all the tests showed no abnormal growths, tumor or anything threatening, though two tests revealed a large blood vessel on the wall of the lower intestine but then after an enteroscopy, there were no large blood vessel found.)  

    I’ve been plant strong for three weeks, with occasional cheese when eating out with friends (that will now stop because my weight loss, 15 pounds so far, may have reached a plateau).  My plan is to have my blood tested again in another month or so to see where my iron levels are, as well as cholesterol.  I’ve also never felt better!!

    My question is about the iron absorption, storing issue…wondering if I should continue taking “chronic iron”.  I appreciate the video on iron being a double-edge sword but I’d like to have more information; what other links should I check out?

    Many thanks for sharing such important information!!

  9. What information is out there about taking Iron Infusion for anemia.  Does Iron Infusion cause the same risks such as Parkinsons, oxidative stress?

  10. Glad I had some smart docs when I went through my time of iron deficienanemia, after not getting help from several others. I didn’t understand about the ‘stores.’ I apparently had had a bleeding ulcer which went undiagnosed (a not so smart doc) when I had a lot of gastric symptoms. (to those who are given a diagnosis of GERD…follow your instinct and get a second opinion.) Anyway, the iron thing….I also was diagnosed with a VERY low thyroid. I was eventually put on a triple dose, 180 mgs of Armour Thyroid along with some other supplements and a liquid iron. It was quite a crash. As time went on I was told to stop the iron, that I checked ok and the ‘stores’ issue was explained. I also started to complain of heart palpitations and the thyroid was lowered, and lowered, and lowered. At some point, I couldn’t get the Armour thyroid any more and I just put off getting another product. A couple years later, it happened again. Sleep disorders, cold to the bone, hair falling out, etc. Just felt horrible! This time I checked out ok for both the iron and the TSH. Changed docs again to an ‘alternative’ doc and was getting a more reasonable discussion of the tests. He found it beneficial to prescribe a single dose of the Armour again. ( it had become available again.) There was some suspicion of Hashimoto’s. I wasn’t tested for it because the single dose of Armour and a single cup of coffee (I use the Folger’s singles to limit what I make) in the morning seems to have turned around the ADD, depression/anxiety and sleep problems. Go figure! Don’t know it this makes any sense to anyone but, I am told that the coffee acts as an upper to excite the brain’s centers that in turn put out the necessary chemicals which affect these chronic disabling issues. I have been on Cymbalta for several years after trying several antidepressants/antianxiety meds that made things worse. I was ready to give up and die. Oh, BTW. I was taking it for terrible Fibromialgia too.

    I took up a raw vegan diet and now not as perfectly raw but definitely vegan. High quality/very low fat. (Your videos and articles help) I feel better than I have for a long, long time. Maybe ever. I don’t want to rock the boat but am getting heart palpitations again. I’ve had all available heart checkups and no serious problems found. I can try taking a little less coffee. I have also been using some ‘herbal’ supplements like Ashwaganda, Astragalus, Holy Basil, Reishi Mushroom, and Ho Sho Wu. I also include some Ceylon Cinnamon which helps with blood sugar balance. My BSugar tests are ok, but helps the cold feeling. I also notice, or think I do, that the palpitations are better when I add some vegan protein powder to my green drink.

    I guess that’s a lot of info. I’M confused, so anyone reading this will be too, I’m sure.

    I’m not trying to get any kind of diagnoses here, but you asked about questions, so my question is….

    Do you see anything glaring here that would tell you I’m doing something right or wrong?

    Thanks for all you do. I read most of your posts and certainly go to your site first when I need to look up some info. Lynn

  11. Dr. Gregor, What are your thoughts and conclusions about the use of Iron infusion? if one’s iron level at 5. It looks almost impossible to get irons levels high enough, quick enough, without Iron infusion. Sincerely, sleepy in Seattle.

    1. If you have a low iron level the most important thing is to find out why. Dietary, menstrual blood loss and losing blood in gastrointestinal tract from a variety of conditions (e.g. ulcers, tumors). Once the underlying cause is determined and treated there are several ways to replenish depleted iron stores and iron levels. In over 30 years of practice I never saw a case where a patient that needed iron infusions even injectable iron can cause problems. I favor gradual resolution through oral supplementation. You need to work with your physicians as each case is individual. If your physician recommends either infusion or intramuscular injection I would have them back up there recommendations with scientific studies as well as full disclosure of the alternatives such as oral therapy. You need to work with your physicians over time as each patients situation is unique.

      1. I’m not sure I understood you correctly Don. So yes or no to iron infusions? My dr wants to give me iron infusions but I’ve been resisting since I’ve always believed our body wants/recognises/utilises organic nutrient/mineral sources. My diet is pure whole food plant based for 21 years now, prior to that vegetarian from birth. About 11 years ago it was found my ferritin levels were at the lowest end of the “normal”. Over the years tried Floradix, Spatone (liquid iron supplements) and homeopathic iron “pills” on and off with no change. From having kept a track of my food intake with Cronometer it appears I just don’t get enough iron from my foods daily. My digestion has never been very good and I have had no success in improving it either (though have made huge efforts to improve it). I’ve been labelled with Chronic Fatigue Syndrome since 2006. I am at my wits end and feel defeated. What to do?

        1. Taking folate with high levels of iron supplements can help you absorb more of the iron (which reduces the often awful side effects of high dose supplements).

          My issue with iron deficeincy began when ill health stopped me preparing meals. Supplementing to 18mg a day isnt enough for me…. I too use cronometer since anaemia. I put my previous diet into cronometer and it came out at 21mg a day. This was made up of a lot of lentils. I tended to have no breakfast other than a handful of nuts, then some sort of pulse based soup and a pulse based burger for lunch. For the evening meal Id have a pulse based stew or curry. I drink soya milk in my barley cup and had the odd bit of fruit here and there throughoutthe day. That was enough to give me 21mg most days. I think the fact it was homemade stuff meant I used more pulses, because I certainly havent found that ready meals come anywhere close to providing the same quality of meals.

          I still cant cook and struggle with the side effects of the iron supplements…. what we need is proper social care so people can get decent meals made if they cant cook themselves- but in the political climate here in the UK thats as likely as pigs flying.

  12. Dear Dr Greger. Thank you for providing us with this fantastic source of nutritional information. I just have one question about iron supplements. Are iron supplements coming from a non-animal source also harmful? I’m taking supplements specialized for vegetarians/vegans (containing B12, Iron, Calcium, Zink, among other) so they don’t contain any blood heme. Should I still be cautious about the iron supplement?

    Background: I’m vegan now and I’ve had a tendency to become anemic since high school (when I had an omnivorous diet), so I think that it would be good for me to eat iron supplements.

    1. There is no need to take iron supplements unless you have diagnosed iron deficiency. The same can be said for Calcium and Zinc. Neal Barnard’s new book, Power Foods for the Brain, reviews the risks of exposure to excess metals such as copper, zinc and iron and Alzheimer’s disease…. just another reason to avoid all supplements except vitamin b12 unless diagnosed with deficiency. You need to remember that about 5% of folks are outside the normal range on blood tests normally.

  13. There is one way to reduce excess iron in healthy adults: blood donation.

    Possible association of a reduction in cardiovascular events with blood donation.
    DG Meyers et al. Heart. 1997


    Donation of blood is associated with reduced risk of myocardial infarction the Kuopio Ischaemic Heart Disease Risk Factor study
    JT Salonen et al. American journal of Epidemiology. 1998


    Blood Donations and Risk of Coronary Heart Disease in Men. A Ascherio et al. Circulation. 2001


    Decreased cancer risk after iron reduction in patients with peripheral arterial disease
    LR Zacharskie et al. J. National Cancer Institute. 2008


  14. Dr. Greger,

    Any plant friendly ways for increasing ferritin? There seems to be a lot of information about boosting iron levels, but what about ferritin?

  15. What about someone newly starting a vegan diet?(been vegan for about a week now) There is absolutely no way to reduce any excess iron? I am a male, and I am considering donating blood, just in case there is a problem, as there might be. Not even over time? that is amazing and disturbing, as sooo many people think that getting iron from meat is so important. I was taught that…but I am like now wait a second….

  16. What can a new vegan do to rid oneself of excess iron. I don’t know if I have any, but it seems like that I might. I am thinking of donating blood if I can, otherwise what else might I do? if my body has excess, will my new vegan diet help my body to NOT absorb any new iron, until the levels drop? how long does this take to happen, if ever?

  17. Hello Dr. Greger. I recently came across articles and interviews by
    Dr. Neal Bernard stating that one should eliminate cast iron cookware
    among other things to help prevent Alzheimer’s.

    As a
    premenopausal, 20-year vegan/once-time vegetarian, I’ve constantly
    battled anemia and low iron levels, so I supplement with iron tablets
    and have considered trying my hand at cast iron again to increase my
    levels. I eat dark green leafys almost every day.

    Should vegan
    and vegetarian women and men really cut out cooking with cast iron for
    Alzheimer’s prevention? Do Bernard’s findings even relate to
    vegans/vegetarians, or does it primarily relate to omnivores? And do you
    suggest getting iron levels tested if we still believe in using the

    Thank you in advance!

  18. Dr. Greger, do you know of any research concerning blood concentration of iron in people who cook with cast iron? Do you cook with cast iron?

  19. Hello Dr Greger,
    I´m taking the Vega One supplement from Sequel Naturals and in the label it says it contains the iron pyrophosphate ( 9 mg per scoop ). Is this heme or non-heme iron? Is it healthy for consuming? Thanks for your time.

    1. Vega One is a vegan company, so the iron they are using should be plant-based and therefore non-heme. According to Dr. Greger’s above video, plant-based iron seems to be preferable to animal-based iron sources, but he recommends getting tested for anemia before taking an iron supplement. Hope that’s helpful :)

  20. Dr. Greger, I’ve been following a 100% whole foods plant-based diet for years now and also exclusively eat certified organic foods. About 8-10 months ago I got some blood tests that showed I was Iron deficient (I strongly believe that this is because I had just returned from a long trip during which I had little to no access to iron-rich plant foods). My doctor insisted that I take iron supplements and I refused, saying that I could replenish my iron levels through a concerted effort to maintain a high dietary intake of plant-based iron. More recent blood tests show that my levels are up but I am still iron depleted. Do you think I will be able to restore my levels over time through diet alone? My doctor says I wont (but of course I don’t just blindly follow her instructions).

  21. I have Crohn’s disease and don’t absorb most vitamins from food or supplements. I was in the hospital and the doctors were ready to give me a transfusion because my levels were dangerously low. I opted to take an iron supplement but not the normal ferrous sulfate that is prescribed. I chose Garden of Life RAW Iron. (plant based) I am happy to report that it has raised my levels and I am almost normal. I like it because it does not cause the upset that ferrous sulfate does.

    1. That sounds great Becky! I’ll look them up. How much did you take daily and for how long before blood levels looked good?

  22. I have been vegan for almost 19 years, prior to that I was vegetarian from birth (a third generation vegetarian). For at least 10 years my ferritin (storage form of iron I am told by GPs) has been at the very lowest end of the range and more recently dipping below it. I have always been reluctant to use supplements, preferring to get what I need from the food I eat since this is the most bioavailable and safe. However my food is mostly not organic and also my digestion has been poor, so dietary sources don’t seem to be adequate.

    What I am wanting to know, is it actually “normal”/ healthy for vegans to have low ferritin? After all aren’t the accepted “normal ranges” based on omnivores? I have never been diagnosed with anaemia, but do suffer from Chronic Fatigue Syndrome for the last 9 years and most GPs and alternative health practitioners say I need to get my ferritin levels right up and I may feel improvement in many of my symptoms?

    I have not known what to do and have never had the courage to take high amounts of or consistent supplements. I have gone through bottles of Floradix, a liquid iron supplement, taking usually a maximum of 20mg per day and then once the bottle is used up leave it for a while. But the health professionals are suggesting much higher amounts, in the range of 100mg per day.

    What is your view on this? Thanks.

    1. In my experience and supported in the literature ferritin levels do run lower in patients on a plant based diet. Another blood check which can be done is Fe, TIBC, %saturated to help sort things out. I have two other comments the first is the issue you touched on… normal levels for tests are dependent on the reference population and the second is that their is a normal distribution within reference populations and by definition normal is defined as where 95% of the population falls. This means that you can expect 1 out of 20 values to be outside normal range but normal. I find it helpful in some patients to look at their values over time. This can be particularly helpful in diagnosing or not over diagnosing some disorders such as low thyroid or low iron. It can also be helpful in that it can avoid labeling a patient with a disorder they don’t have. If you have taken iron supplements and your values and more important your symptoms haven’t improved then that would make it more likely that your low ferritin level is normal for you. It is also why you need to work with your physicians to help sort these things out. Finally excess iron in the body is not helpful. Reading Neal Barnard’s most recent book, Power Foods for the Brain, discusses the factors associated with dementia… iron is one of the metals along with zinc, copper and aluminum which have been implicated. Good luck.

      1. Thanks for your response. Other markers such as Serum Iron, Transferrin, Transferrin Saturation as well as Serum Ferritin are usually all tested at the same time and they were OK until this last test where even the Saturation has dropped to 15% (normal range 13-45). So I guess it’s not looking too good. Those of the more holistic practitioners like to see levels of ferritin at around 100 ug/ L (normal range 15 – 165). Mine is 18. To bring levels up to this recommendation would require high doses, probably over an extended period and I was afraid of doing this? Unless I got it up to the levels they want to see, I guess we can’t tell for sure if the low levels are affecting me or not?

        1. Hi Tania,
          There are some really good plant based iron sources out there. I also have a very low ferritin level (13) and I have been working to improve it. I can get it up to 30 if I am diligent with supplementation. You should take your doctors advise. You have Chronic Fatigue Syndrome and you might just feel better. I know I do when my levels are up. BTY I was low even when eating meat daily.

          I don’t believe we are the population they are talking about regarding too much iron–we don’t absorb enough.

          1. Thank you for sharing your experience. I am glad to know you do feel a difference when your levels are higher…. I do realise it is largely the meat-eating population that needs to take heed, but I think it also needs consideration when advised to supplement significantly and regularly…Not meaning to sound arrogant in any way, but I always consider my doctor’s advice before taking action on it. Their knowledge of true nutrition is limited…What my main query was, was whether lower ferritin stores as evident in vegans is actually what is truly normal and healthy?

            1. Well you could always make the determination of whether your iron stores are normal for you based on your signs and symptoms:

              Anemia symptoms vary depending on the cause of your anemia but may include:

              Pale skin
              A fast or irregular heartbeat
              Shortness of breath
              Chest pain
              Cognitive problems
              Cold hands and feet

            2. And I would add hair loss. My hair and eyebrows thin.

              For me personally as well as patients, friends I have spoken too the feeling of being anemic is stifling. Going up stairs become an issue.

              If you feel fine then your low iron stores are normal for you.

              1. My hair loss IS a problem…Wonder how much I should supplement daily? Have had up to 20mg per day, but levels have still gone down. I wasn’t confident to take higher doses.

                1. What did your doctor say? 20 mg 3 times per day? It can upset your stomach but I don’t have that problem with the plant based supplement.

                  1. He suggested an injection ages ago, but I declined. Another doctor I saw, who has more of an interest in functional medicine gave me some tablets to trial and I think the dose was about 100mg, but I forget. I didn’t take them because they were synthetic and had folic acid in them as well (which is a synthetic form of folate that is not recommended) and I prefer to take food source supplements. Besides they were tablets and I don’t seem to break down tablets very well, and prefer liquid iron supplements….So I have found some more suitable forms but am probably not taking a high enough dose. At one time I tried to take 20mg twice a day but it messes with my digestion which is already sluggish anyway, so I went back down to 20mg per day.

                    1. Yes i also take the liquid plant based. I end up with indigestion if I take too much. All I can tell you is as a runner I would never consider walking around low. (even with supplementation I have never had a level above 30) 20 mg isn’t enough for me. It doesn’t budge my ferritin levels. And if I don’t take a supplement it is low whether I am vegan or not. I eat high iron foods. Maybe one day things will change but right now I need to supplement.

        2. I’m not a fan of treating numbers in isolation. There are some videos which show you can enhance iron absorption by eating garlic and onion see… http://nutritionfacts.org/video/new-mineral-absorption-enhancers-found/. If you feel better with higher iron with supplementation as Veganrunner mentioned than I would favor its use. You need to work with your physicians and make a decision that is best for you. In dealing with complex systems like human metabolism there probably isn’t a “right” answer. Good luck.

          1. I’ll take a look at those videos and eat more garlic and onion. True, there isn’t a “one size fits all” prescription. Thanks everyone for your assistance.

  23. Hi Doctor, what kind of Iron is the one you mentioned when you talked about the supplements? If we take non-heme iron supplements there’s no risk right? Because our body can regulate it.
    Thanks for your time!

  24. Hello,
    I have been on a Vegan diet for the last 2 years.
    Recently I have taken a blood test to monitor if everything is alright.

    The result were that I have elevated iron levels in my blood.
    I am not taking any supplements or eating any rich iron foods (that I know of).
    Is there anything that I can do with my diet to reduce the iron in my body?

    1. Hi melliforte,

      That is a really good question. I don’t see any mention of using cast iron in this research. I quick search and I found one paper talking about cast iron cooking and it’s ability to help reduce iron-deficiency anaemia. It did not help. This is not to say no iron is leached from pans, it can. Many older studies claim cooking with cast iron can increase iron levels, especially depending on what you cook (acidic foods in iron pots will enhance iron absorption). So yes, if you are post-menopausal it may be wise to first consider your total dietary sources of iron, and then look to see how much cooking you do in a cast iron pot. I would not say throw it away, but be careful of overdoing iron from cast pots and pans. Plant-sourced of non-heme iron are preferred. Hope that helps.


  25. I just read a BBC article (see link) about using a lump of iron in a soup pot and then adding lemon juice. This was for populations with severe iron deficiency.
    They also mentioned, “What’s missing from their diet are iron-rich foods, particularly red meat. Green leafy vegetables, such as spinach, are not as rich in iron and mustn’t be overcooked if they are to offer any benefit at all.”


    I’m wondering how Dr. Greger would respond to this article?

  26. there is an error on the spanish subtitules. On the minute 0:43 there is some part of the spanish subs that are in english instead of spanish. Please fix it .

  27. I have thalassemia and I was told to not eat lentils because of how high they are in iron…just as I should not use iron pills. Is there any truth in that or is there something I should stay away from food wise?

  28. I eat the daily dozen and drink 5 cups of tea all day- did you know so many of the healthy foods have iron blocking components?! I’ve read calcium, oxalates, tannins, polyphenols, phenolic acid, and phytate inhibits absorption. Basically, my entire diet, though rich in antioxidants, is high in inhibiting factors! (legumes, berries, greens, cocoa, herbs, spices, apples, greens, nuts and seeds are rich in one or more of these anti-nutrients- which i eat a lot of).

    Now, i have since cut out tea to just rooibos as i think it is more an inhibiting issue with me rather than consumption as chronometer always says i meet my RDA. Does anyone know if hickory/carob/dandelion coffee substitute is low in tannins?? I love that stuff…

    Also I would love any ideas on how to boost my levels again. I am also on 2 months of supplements just to get the levels up again but then I’m hoping to maintain with diet. I’ve invested in a “lucky fish” which is made of iron to be used in cooking to leach into the dish for after I run out also. Any food or recipe suggestions would really help me out. Thanks in advance!

    1. Teesha: Here is a NutritionFacts article covering this topic: http://nutritionfacts.org/2012/11/01/how-to-enhance-mineral-absorption/ Also, Dr. McDougall also has some interesting observations on the topic of anemia: https://www.drmcdougall.com/health/education/health-science/common-health-problems/anemia/
      Also, you might consider investing in a book called Becoming Vegan, Express Edition. This book is recommended by Dr. Greger and covers this issue in good detail. By getting this book, you would not only gain advice on how to deal with iron absorption, but you would be getting a great all-around reference book for many different nutrition substances.
      Question: Have you been diagnosed with anemia? Or are you just assuming you have a problem?

      1. Thank you both for all your help! I have actually been diagnosed at 11ug/L serum ferratin (15-165 is normal range).
        Thank you for the reading material i will get on that! :)

    2. HI Teesha – in addition to moderator Thea’s comments and great resources she highlighted, may I just offer a few words to help reduce your concerns? While there are iron absorption blocking components in many anti-oxidant rich plant foods as you identified above, when we eat balanced meals and pay attention to Vit C rich foods, we generally don’t have to be too worried about the inhibitory effects on iron as being too significant. For example a lentil soup, (lentils are high in phytates), because it is cooked, will have some reduction in the phytate content. In addition, many yummy lentil soups also contain tomato (or if not you can always add brocooli or peppers or a side salad or an orange for dessert ….) which boosts Vit C which enhances absorption of iron. I’m also a fan the the “Lucky Fish” – nice of you to support such a good cause too!

      As for tea specifically, the high tannin content can definitely interfere with absorption of minerals like calcium and iron when consumed with a meal. You can get around this by spacing tea intake 1 hour before or after a meal, or do as you’ve done and choose a rooibos or herbal tea instead.

      In the Becoming Vegan book below, I believe the authors also cite evidence that vegetarians do not have higher rates of iron deficiency that non-vegetarians. It would seem the answer lies in the balance of foods at meals, attention to cooking methods and in the case of tannins in tea, not drinking it with meals. I hope this helps!

  29. hi dr greger,

    i would loke to know what can i eat to work out my iron deficiency? i have read that because of oxaloc acid, spinach is not very good idea

  30. There is a high sulfur content in the water well at my home. I was told that this makes it unhealthy for me to drink my tap water or cook with it,is this true?

  31. Help! I am anemic and am scheduled for major surgery in three weeks. They just prescribed 975mg per day of iron. I took one 325mg pill yesterday and was sick for hours! All of the food based iron that I am researching has such low dosages. What can I do?

    1. While this website focuses more on what you can EAT to minimize your need for iron supplementation, I understand that your question is based on a urgent need to quickly build up your iron stores before your surgery coming up in 3 weeks. When I review the Pubmed data base, I found a few suggestions which you may already be aware of. Are you taking coated iron tablets? If not that may help. Are you taking the pills on an empty stomach? While this is preferred, to cut down on stomach upset taking after a meal may help. Both of these options are ones you should discuss with your health care provider now, and certainly you need to advise dr of your exact symptoms after taking the pills. Be specific about your reaction: symptoms, timing and how many times you became sick, so dr. can determine if change of dosage, other changes needed. Best of luck for your surgery and then review carefully Dr Greger’s videos on anemia so you can get your iron level where it needs to be as you recover.

  32. Does anybody know about iron in liposomes supplements such as Infisport (http://www.infisport.com/infisport_en/productos.php?idProducto=60)? They are supposed to reduce the oxidative stress, since the iron is inside liposomes…
    I couldn’t find any article in PubMed, only this compilation of articles, but I can’t say how trusty they are… http://www.zambon.es/Content/document/accordion/fisiogen-ferro-monograf%C3%ADa-de-producto.pdf
    Moreover, I could not find out where the iron comes from or in which form it’s presented inside the liposomes.

    1. Erola,

      it seems to be very sketchy and not backed up by science. I couldn’t find any reliable info to back up those claims, neither. I wouldn’t trust it.

  33. Hi Dr Greger, I went through your article on the mechanisms of Iron Absorption and I was left rather puzzled. I saw that Diagram you posted about Heme Iron passing through the intestinal barrier, but I also took a look at the other side of the diagram where Ferrous Iron was just passing right through too. Ferrous Iron can be derived from plants so does that not mean that it cannot be regulated either??

    1. Hello! Iron metabolism is very complex and tightly regulated by the body. To simplify, heme iron is very easily absorbed into the body, and high intake of heme iron can thus lead to toxic iron overload. Non-heme iron is less readily absorbed and is generally not associated with the development of iron overload. To absorb enough, but not too much, iron, choose non-heme (plant) sources, and eat them along with foods that help absorption, like oranges or other vitamin C foods. -Dr Anderson, Health Support Volunteer

  34. I’ve been plant-strong since 2016 and my ferritin is a low 20. My doctor wants me to supplement with iron to get it up to 50. I’m not wild about the idea, but I also don’t want my iron to go to low, and it’s heading in that direction. I’m wondering if low ferritin is typical of vegans? What can we do? I eat plenty of iron-rich foods with Vit. C, and avoid tea with meals. I don’t drink coffee.

  35. Hi, Diane! Some women lose more iron than they absorb, and can become iron deficient.

    According to Medscape, reference ranges for ferritin are

    Males: 23-336 ng/mL

    Females: 11-306 ng/mL

    Although you are in the low end of this range at 20, you are still within the reference range. Iron is not in the “higher is always better” category, as too much iron can be harmful. If you are showing signs of deficiency, such as fatigue or shortness of breath, then a plant-based supplement could be a good idea. Otherwise, you are probably fine. You can find everything on this site related to iron here: https://nutritionfacts.org/topics/iron/ I hope that helps!

  36. https://www.youtube.com/watch?v=rfpM37JmQHY

    Dr. Pam Popper just posted (a week ago) her youtube video titled: “Fat Soluble Vitamins Do Not Need to be Consumed With Fat”. I’ve enjoyed some of her latest videos, and participation in The Real Truth About Health, etc.

    She has, in this one video, countered two paradigms 1) eating some fat with fat-soluble nutrients and 2) whether Vit C increases non-heme iron absorption. She noted one study on Vit E (not linked) in support of 1) but tied a similarity conclusion to 2) based on statements like our ancestral humans “survived” therefore neither of these are issues, no reason to worry about it, the whole point of this video is to encourage people to stop making healthy eating harder than it needs to be.

    Begs my question, is she speaking about facts or convenience? She comes across as factual but uses arguments like those above rather than pointing to or referencing studies (no links provided).

    I wonder what Dr. Greger would say, and it would be great if someone would throw him this scenario in a Q&A.
    With a quick search, the following nutritionfacts videos and 2 studies state the paradigms most of us believe:






    1. Hi David,

      I am a volunteer for Dr. Greger. Thank you so much for your question.

      Overall, vitamin E (and other fat-soluble vitamins like A, D, and K) are more absorbable with the presence of fat. The research is pretty clear on this. However, one study showed that even if a vitamin E supplement is consumed with water, some of that vitamin E is absorbed, especially if the person has a low vitamin E status. If you add fat, then the vitamin E supplement was absorbed in a greater amount. However, we don’t know the implications or outcome of having excess fat-soluble vitamins. Some research suggest that excess vitamin A can actually be detrimental. For somebody who eats a poor diet, It would make sense that eating a small amount of fat in the form of nuts or seeds with fat-soluble vitamin-containing foods might be beneficial for them to absorb what they can. For somebody who eats a very nutrient-dense diet, it may not be as important to absorb the maximum amount possible. We don’t seem to have enough research to know the optimal intake amount of those vitamins.

      As a side note, I will say that her logic and rationale for Dr. Popper’s conclusions is fairly poor in the video you posted. She stated that because one research study suggests that vitamin E absorption can be absorbed without fat, that other fat-soluble vitamins would also be lumped under this category. This is very flawed logic and unscientific in my opinion. It is also unscientific for Dr. Popper to say, as you mention, that because our ancestors made it without adding oil to vegetables, that that is the optimal dietary recommendation we should be following today. She also didn’t seem to know how to pronounce “chylomicron”, which is the molecule that transports fat from the intestines through the lymph and into the bloodstream. The fact that she didn’t seem to be familiar with that word seems to me a red flag.

      I hope this answers your question!

      1. Thanks for the detailed answer Cody.  We all appreciate very much the attention Dr.Greger’s Health Support Volunteers bring to keeping these video discussions alive and well. Cheers

  37. Some new research concerning iron and cancer:

    Cells don’t cope for long without iron, which is needed to make DNA and other essential molecules. When a rise in pH causes iron depletion, cells stop dividing and eventually die. The scientists think this happens because lysosomes free iron from the molecules that transport it, something they do best at a pH of 4 to 5, the approximate acidity of a tomato.

    Because lysosomes are known to be essential for cancer-cell proliferation, the discovery suggests a potentially new way to fight tumors: starving them for iron. In recent years, Birsoy’s lab has devised a number of innovative ways to kill cancer cells by blocking their access to essential nutrients; now iron depletion promises to yield yet another weapon in this arsenal of potential drugs.


  38. Dear Dr. Gregor, I’ve been chronically low in iron for years, although stopped taking supplements 3+ yrs ago as my stores were actually too high, but blood levels low. What can cause this? (my liver is fine “which makes hemochromatosis unlikely”.) I’ve heard “infammation” but how/where? Do I really need to go to a hematologist? Thank you! Kate

    1. Kati, As a nurse I’m concerned that you say you’re chronically low in iron. That means you’ve been tested and I’m hoping you are working with your healthcare provider to clarify a monitoring/treatment plan. Certainly if you are having symptoms (for ex. fatigue) working with your doctor to clarify answers is important and to determine if working with a hematologist is appropriate. As far as inflammation, I’m not aware that low iron could be a result of inflammation. When I checked with Medline data base, studies cited high iron as being associated with inflammation. I hope you can get some answers to the low iron and meanwhile keep eating a whole food plant based diet to promote your good health.

  39. My ferritin is 13.
    I have been going to doctors for a few months now regarding sudden onset of very random and diffuse symptoms: reflux, side pain, diffuse pins and needles, diffuse muscle twitches, diffuse muscle pain, shortness of breath. I’ve been worked up and imaged and the only abnormal value I have is low ferritin. No doctor seems to take the low ferritin all that seriously. I have found some information on iron deficiency causing symptoms that I describe above. Does Dr. Greger have any insight on this?
    I eat a plant based diet. On most days I get in my “daily dozen”.
    I take B12 and vitamin D–and recently magnesium to see if it helps with muscle twitches

  40. What about iron supplements from plant sources?
    Namely chelated iron (iron bisglycinate)?
    I am afraid I may be susceptible to anemia bc of extremely heavy monthly flow,
    and since Im vegan anyway I wanted to know if theres any science
    on iron supplementation from plant sources.

  41. Meffert,

    There are essentially two forms of naturally occurring iron, plant based iron typically occurring in the insoluble ferric (Fe3+) chemical form and iron from animal sources contained in hemoglobin and myoglobin, that is typically complexed as the more absorbable ferrous (Fe2+) form. https://www.ncbi.nlm.nih.gov/books/NBK448204/

    There are significant differences in absorption between the two, with the animal-based products much more vs the plant based but…. it depends on a number of factors. With that said you can effectively change the percentages by adding some vitamin C and/or other organic acids which will change the form making it more absorbable. Drinking juice or eating fruit with your plant-based veggie burger will result in a 67% increased iron absorption rate as an option. Good article to reference: https://spoonuniversity.com/lifestyle/the-difference-between-plant-based-iron-and-iron-from-meat

    If your comparing foods a by weight comparison soybeans have almost twice the iron of beef. But only about 1.4-7% of the iron in soybeans is absorbed. But wait….that’s in a science based experimental setup. If you work with other food ingredients including acids and vitamin C you can change this radically. https://pubmed.ncbi.nlm.nih.gov/1745900/

    As to the iron bisglycinate….. its a complexed form that is highly absorbable and I have found it to be useful for anemic patients, without causing constipation which is common with ferrous sulfate iron supplements. See your healthcare provider, address the heavy periods and have a conversation regarding avoiding anemia.

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

    1. oh, that is good to know!
      my question was more about, if the chelated Iron, even If it is from plant sources, since it is highly absorbable, will also Put me at risk for cancer etc by my body absorbing too much? is it Just the heme Iron or will the plant Iron also bei harmful, is it possible that i absorb too much since it is chelated?

  42. Hello! I am 22 years old and have been on a Whole Foods Plant Based diet for 7 months now with no prior conditions. I am super enjoying it but I just got my bloodwork back and although my iron levels are normal, my percent saturation for iron is low. I looked up foods to pair with high iron foods but I feel a bit discouraged because I feel like I eat a lot of foods with iron already and there seems to be contradiction in iron absorption… For example: Lentils and tofu have been stated to have a good source of iron (via the food revolution network) but phytates and calcium can inhibit iron absorption… and phytates and calcium are abundant in legumes, and soy. I am feeling confused. Any advice?

  43. Good for you being on a WholeFood Plant Based diet and doing well, although sorry you are feeling discouraged about your iron saturation. That may be a temporary reading or insignificant wince your iron levels are normal and you are feeling well. However, there may be other ways you can increase the iron absorption if you are concerned. Check out this video for some additional ideas: https://nutritionfacts.org/video/new-mineral-absorption-enhancers-found/
    Hope this helps.

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