Can Folic Acid Be Harmful?

Can Folic Acid Be Harmful?
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New research on the human metabolism of folic acid suggests natural sources of folate are preferable.


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

Folic acid supplements, which are recommended for all women of child-bearing age to prevent birth defects. Harmful, harmless, or helpful? In other words, vitamin and panacea, or genetic time-bomb?

I do not recommend folic acid supplements; I recommend folate—from the same word root as foliage—found in dark green leafy vegetables and legumes.

But everybody knows no one eats greens and beans every day, so the government started fortifying our food supply with folic acid in 1998. Folic acid, though, is not the same thing as folate. But it’s cheaper and more stable in pill form, and so that’s why they use it instead. In fact, folic acid is a synthetic chemical not found in nature at all. But, studies on rats found that there’s an enzyme in the liver that basically changes it into the natural form.

Studies keep coming out, though, linking folic acid supplementation with diseases like breast cancer and colon cancer. So yes, it lowers the risk of birth defects, but may raise our risk of cancer. But, wait a second; spinach doesn’t raise our risk of cancer. Beans and greens lower the risk of both birth defects and cancer. It was a big mystery until last year, when scientists figured out we’re not rats.

It’s hard to study human livers, because people tend to need them, but sometimes an organ donor dies, and there’s no one to take the liver. And so, scientists were finally able to see if what happens in rat livers actually happens in human livers. And it turns out that the enzyme that converts folic acid in pills into something our body can actually use, is 50 times less active than in rats. Less than 2% of the activity we thought it had, based on the animal studies.

So, because our enzyme is extremely slow, people who take folic acid pills have lots of this synthetic folic acid circulating in their bodies, and that’s what we think may be behind the elevated cancer risk. Whereas beans and greens every day offer the best of both worlds.

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

Folic acid supplements, which are recommended for all women of child-bearing age to prevent birth defects. Harmful, harmless, or helpful? In other words, vitamin and panacea, or genetic time-bomb?

I do not recommend folic acid supplements; I recommend folate—from the same word root as foliage—found in dark green leafy vegetables and legumes.

But everybody knows no one eats greens and beans every day, so the government started fortifying our food supply with folic acid in 1998. Folic acid, though, is not the same thing as folate. But it’s cheaper and more stable in pill form, and so that’s why they use it instead. In fact, folic acid is a synthetic chemical not found in nature at all. But, studies on rats found that there’s an enzyme in the liver that basically changes it into the natural form.

Studies keep coming out, though, linking folic acid supplementation with diseases like breast cancer and colon cancer. So yes, it lowers the risk of birth defects, but may raise our risk of cancer. But, wait a second; spinach doesn’t raise our risk of cancer. Beans and greens lower the risk of both birth defects and cancer. It was a big mystery until last year, when scientists figured out we’re not rats.

It’s hard to study human livers, because people tend to need them, but sometimes an organ donor dies, and there’s no one to take the liver. And so, scientists were finally able to see if what happens in rat livers actually happens in human livers. And it turns out that the enzyme that converts folic acid in pills into something our body can actually use, is 50 times less active than in rats. Less than 2% of the activity we thought it had, based on the animal studies.

So, because our enzyme is extremely slow, people who take folic acid pills have lots of this synthetic folic acid circulating in their bodies, and that’s what we think may be behind the elevated cancer risk. Whereas beans and greens every day offer the best of both worlds.

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Doctor's Note

Also check out these videos:
Some Dietary Supplements May Be More Than a Waste of Money
Risk Associated With Iron Supplements
Dietary Supplement Snake Oil

And check out my other videos on folate. If you’re worried about the gassiness of beans as a source of folate, check out my blog post Beans and Gas: Clearing the Air

For more context, also see my associated blog posts: Breast Cancer & DietSoy milk: shake it up! and Are Multivitamins Just a Waste of Money?

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

111 responses to “Can Folic Acid Be Harmful?

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  1. Please feel free to post any ask-the-doctor type questions here in the comments section and I’d be happy to try to answer them. And check out the other videos on folate. If you’re worried about the gassiness of beans as a source of folate, check out my blogpost Clearing the Air. Also, there are 1,449 other subjects covered in the rest of my videos–please feel free to explore them as well!

    1. I have a genetic defect known as MTHFR, which makes it impossible for me to utilize folate from food or conventional supplements. I must take methylfolate supplements twice daily for life, as a result. Although I realize this does not entirely return me to “normal” health, I am extremely healthier with the supplement than without. Can you speak to those who have issues with folate utilization?

      1. For those unfamiliar, humans have a gene that
        regulates the activity of an enzyme called MTHF-reductase. This enzyme is
        responsible for methylation or in layman’s terms, activation of several B
        vitamins, in particular folate. This is an important enzyme as the body only
        uses folate in the activated form and methylation is one method the
        body uses to remove toxic intermediaries of metabolism and other substances
        that might otherwise cause harm. Inability
        to activate folate can contribute to symptoms including fatigue, depression and
        elevated homocysteine that can contribute to cardiovascular disease. During pregnancy this enzyme helps provide
        L-methylfolate which is required for proper development of the neural tube or
        nervous system of a developing fetus. It is estimated that up to 30% of the
        population can possess one or more genetic variants of the MTHFR gene. If you have this genetic trait, the activity of MTHF-reductase can be reduced by 30%-70%. Taking a high quality supplement that
        contains folic acid as L-methylfolate and B12 as
        methylcobalamine, can address this deficiency and help reverse symtoms. For the majority of people who don’t possess this trait, getting most of your nutrients from food is always your first choice. You might like to check out these other interesting videos on supplementation: Vitamin Supplements Worth Taking and Should We Take a Multivitamin

        1. Thanks for your excellent and detailed response. I wonder if the high prevalence of MTHFR mutations warrants more extensive screening testing for this mutation, at the very least in women who are pregnant or planning to become pregnant. Do you (or other NF viewers/readers) know the cost of this test and whether insurance generally covers the cost?

          1. Linda provided some good resources! I’m not an expert on testing methods and unsure what insurance covers the testing. Perfect question for your doctor and healthcare team. Let us know if you find out anything.

        2. Can MTHFR mutations be compensated for by increasing intake of Folate from food? My husband and I both have these mutations. Using CRON O METER I increased our Folate goal to compensate for the percentage that we are not Methylating. My deficit is reasonable to make up for with generous portions of greens and beans, but my husbands …far exceeds his appetite. Is it reasonable to assume that by consuming the extra % of Folate through food that the body isn’t able to grab that I am compensating for the mutation?

          Our Methyl Folate supplement bottle says “…if you are pregnant or tying to conceive consult your health care professional before taking…”. It seems that would be the time one would need it the most. Any insight into what the concern might be? BTW my healthcare provider has no clue about MTHFR mutations. Any advice on finding a knowledgeable professional to consult on this?

          1. Hi D A, Unfortunately the folate in food must be converted into a usable form in the body. In people who have the MTHFR gene variant the enzyme responsible for this conversion has reduced function and for this reason those individuals need to take a methylated form of folate. By doing this you will bypass the step where the enzyme is needed. So the short answer to your question is no, you can not compensate for an MTHFR gene variant by taking more folate in your diet.
            The most likely reason your bottle says to consult a health care professional if you are pregnant or nursing is because pregnant or nursing women often have different nutrient requirements than the general population so most manufactures will put a similar warning on their labels. In addition pregnant women are at risk for having children born with neural tube defects if they don’t get adequate amounts of folate so it’s best for them to take folate under the direction of a healthcare provider to assure adequate amounts.
            Finally, you could try doing a search for a certified Functional Medicine Practitioner in your area by going to the website if the Institute for Functional Medicine Click on the find a practitioner link and search by state or zip code. Any certified practitioner should be familiar MTHFR and with methylation related problems.

    2. Could someone from the team…Darryl : ) please address Monica et al. regarding this MTHFR issue? I’ve never heard about it.


    3. Dear Dr. Greger,
      I have been taking vitamin supplements for more than 5 years. A multivitamins and a B complex so I think I’ve been taking about 500 mcg of folic acid a day. About 4 months ago I had my yearly blood test done and the result was scary. My folic acid levels (called here in Spain “folic acid erythrocytes”) were up to 1386 ng/mL when the normal parameters are between 112-508ng/mL. My doctor told me to stop taking the supplements and had me do another blood test about a month later. My levels had risen to 1637 ng/mL!! I don’t know what to do and neither does my doctor. She says she’s never encountered these results so of course now I’m worried!!
      What should I do? Am I at a big risk of getting cancer because of these folic acid levels? Is there a way I can cleanse my blood to get rid of the folic acid surplus?
      I stopped taking the supplements but do I need to eat less folate as well, at least until my levels return to normal? I usually have a green smoothie every morning.
      Many thanks for your help!!

      1. Kathy B

        From your folic acid levels rising even after you stopped taking supplements containing it, it would seem that folic acid is hiding in one or more of your foods. Perhaps it is in the bread you eat or some other food product made from flour? Good luck in finding it?

    4. I have rheumatoid arthritis and have been on Methrotrexate (25 mg injected once a week) for almost a year now. I have been given folic acid (1 mg/day, except on MTX day) to counter the side effects of the MTX. I recently came upon your piece on the problems with folic acid. For someone in my position, is there any reason I can’t get enough folate from what I eat to counter those side effects? Any reason not to use food instead of the folic acid supplements? I’ve been eating plant based/whole foods for the past five years and on the Paddison Program for RA for well over a year now. The Paddison Program involves a combination of exercise and food — plant based, whole foods, low fat — to control RA. I am largely pain free now though I still have some swelling and stiffness of joints — but much improved. I don’t want to jeopardize these improvements with rising AST/ALT levels (which folic acid is said to prevent). I’d really appreciate getting clear on this. My impulse having watched your video is to ditch the folic acid and keep eating those leafy greens and legumes. Thanks!

    5. Dear Dr. Greger,

      I am living in Serbia ( my background is also medical , but I would like to work outside the classical system of western medicine like you), where there is a fortress of meat eating and where i am trying hard to build a consulting business for helping people through a plant based nutrition get healed from various diseases.
      Would you please be so kind and answer my market research worksheet questions , it s necessary for me to have sufficient information about the problems, fears , desires and also trends of the “nutrition niche “, so I can create more value and meet the needs of sick people.

      Thank you so much. hanna

      please send me your email, so i can forward you the pdf attachment , in the subscription news it says no reply..

      1. Great point, Eve. Some nutritional yeast labels say “Folic Acid” is added. Others say “Folate” is added. I think you’d need to talk with someone at the company to find out if when they say folate, that’s truly what they mean. You can also get nutritional yeast with no vitamins added, which may be the best way to go. You can then supplement B12 as 250mcg daily or 2500mcg weekly and folate if needed.

        Dr Anderson Health Support Volunteer

        1. dr. anderson, thanks so much. that’s the conclusion i have come to as well. i actually did put a call in to the company this morning. i will let you know what i find out.

        2. dr. anderson, i made contact with the makers of red star yeast and it is fortified with folic acid.
          there are other makes that are “non fortified” but at least twice as expensive.

    6. I wrote the following message to an RD working for HUM Nutrition:

      “I found your Hair Sweet Hair product on Amazon searching for products that combine Biotin and Fo-Ti, and was just about to order when I noticed that it contained Folic Acid. I originally read that folic acid in supplements might not be recommended from Dr. Joel Fuhrman’s website, but then checked that with Dr. Michael Greger’s helpful website, where I found this:

      Consequently, I will not be ordering this product. I was a bit surprised to discover when I went to Hum’s website to learn that they employ so many dietitians, and yet still include this questionable ingredient in (at least) one of their supplements. Perhaps you could recommend changing the formula (and let me know when they do)?”

      Here’s the response I got:

      “Dr. Greger cites one study to show this, and the overwhelming data shows that folic acid is still considered to be safe, especially among women of childbearing years who may not get adequate amounts of folate in the diet.”

      What should the average person really take away from these two conflicting positions, and the grey area that may exist between them?

      1. the take away is eat real food. lots of leafy greens to get folate and other whole foods for the other micro and macro nutrients so you don’t have to take fake vitamins.

      2. Here’s a more recent review of this complex topic. The take-home is that you can get too much folic acid, and in some situations, this can lead to increased cancer rates. It doesn’t happen in everyone, but it’s still a potential problem. On the other hand, dietary folate (as in leafy greens, citrus, and beans) is not associated with increased cancer risk. Ideally, get folate from foods.

  2. What about folic acid supplements for vegans during pregnancy? Healthy vegan diets are high in folate so it seems possible and certainly preferable to get this nutrient from food rather than supplements.

    1. The fact that folic acid is attributed to the diseases mentioned in the video makes taking it as a supplement out of the question in my opinion. Its similar to taking a beta carotene supplement, what they have done is isolated a single carotenoid and super concentrated it in a pill. The prenatal supplements are truly not necessary, especially if one is eating as health a a plant based eater.

      Check our Dr. Greger’s video of the dangers of Iron during pregnancy and the vitamin supplements worth taking.

      1. I’m also very interested in this manner.
        Since both question and answer were provided 5 years ago, is there any new information regarding this?
        Is there any significant finding in the last 5 years that is somewhat changing the stand on folic acid and pregnancy?

  3. Should we avoid folic acid in supplements completely? I’m looking into B-complex supplements and almost all of them contain 1 mg of folic acid. Thanks for all the awesome videos!

    1. The study measured folic acid at 1 mg or higher. 1 mg is considered the upper tolerable intake of folic acid. They note that .4 mg of folic acid in individuals gets metabolized to folate but higher than that and we get unmetabolized circulating FA which is harmful. If you are eating a well balanced plant based diet the only supplement you would need is vitamin b12. A B-complex is not necessary.

      1. Thank you so much for the reply! Yeah I was also wondering if B-complex was necessary, I heard from some sources that your body really wants all the B vitamins to be taken together. But Dr Greger seems to recommend B 12 supplement only.

        1. It is true that almost all whole plant foods contain a mix of the b vitamins, but just because they lack b12 doesn’t mean that the other b vitamins are ineffectively used, nor should we have any reason to believe so.

          1. I guess when I really think about it, it makes sense that since we can get the rest of the B vitamins from a plant-based diet, the only supplement we need is B 12. Thanks again for your reply :)

  4. There are food based vitamins such as MegaFood, which offer folate in the normal food form, from broccoli. 40 percent of population has MTHFR genetic mutations which affect the absorption of folate, to varying degrees. The synthetic folic acid is probably more harmful to these people and on top of that, they may need food based supplements-depending on the health of their gut and which mutation they have. It is insane that folic acid is added to everything.

  5. I was on 5mg folic acid daily to offset harmful effects of methotrexate (for Rheumatoid Arthritis) I’m currently off the mtx but has the 5mg a day possibly done my body harm? I know the mtx probably has! :(

    1. 5 MTHF is the folate that is actually used in the folate cycle to to make B12. If your folate is not able to be converted to 5-MTHF because of an enzyme deficiency (MTHF reductase) then this is the one that will keep your B12 levels up, your homocysteine levels down and keep your methylation happy. Folic Acid (provided by law in all enriched products) is not found in nature but is quite shelf stable in foods, and requires several more steps to turn into 5-MTHF. We are provided so much in our over consumption of enriched foods (think anything with flour that is not 100% whole wheat) that the build up of Folic Acid can be toxic and cause its own problems. And as chicavegana comefrutes commented above, a large segment of the population has the defective MTHF reductase enzyme which greatly puts them at risk.

  6. Hi Dr. Greger: I was wondering about Perfect Prenatal by New Chapter Organics as is is a whole foods vitamin which includes “folate” not “folic acid”. Also, I am wondering about Seeking Health L-5 MTHF 1000 which claims to provide only folate as “metafolin” for people with the MTHR issue. In general, are vitamins containing “folate” no “folic acid” ok?

    1. I think Dr. Greger would stick to his assertion that getting vitamins from whole foods and not pills, will serve our bodies better. Beans and greens are great, affordable sources of folate. :) Hope that helps.

  7. Dr. Greger, you need a video on MTHFR defects. Some people do process folic acid, but 40% of the population have an MTHFR defect that causes them not to process folic acid into folate. So your recommendation that everyone eat beans and greens is right on target; however, people with MTHFR defects should take a multi and B-complex containing the natural form of folate. In fact, there are studies that link pregnant women who have this defect and take prenatal vitamins containing folic acid are at much high risk for premenopausal breast cancer. That’s 40% of women! (MTHFR polymorphisms, dietary folate intake, and
    breast cancer risk: results from the Shanghai Breast Cancer Study. Shrubsole MJ1, Gao YT, Cai Q, Shu XO, Dai Q, Hébert JR, Jin F, Zheng W.

    Since my entire family has one or two MTHFR defects, I’ve been reading more and more and am astounded by the statistics, some of which you state that are probably related to MTHFR people ingesting folic acid-fortified foods and increasing incidences of various types of cancer, but it’s more than that. It probably has a hand in every western degenerative disease. As you know, methylation is essential for the proper function of most body systems and cellular processes. It is also needed to support glutathione production which neutralizes free radicals, helps the body process toxins and supports proper DNA synthesis and repair and other metabolic processes. It is required for the creation of every cell in your body. Consequently, it is easy to see how this mutation could have a role in many conditions and diseases. And while I agree that if one is a vegetarian or vegan and eats beans and greens and does not take folic acid or eat fortified foods, their folate status will likely be good enough to not have problems with MTHFR; this is unfortunately not the case for the majority. Please do a video on MTHFR. 40% of the population is a lot of people. Get this, 98% of autistic people have this defect. No wonder they may have trouble processing toxins. Great site. Love the information. You do a great service to the many seekers of nutritional and medical knowledge! Many thanks!

      1. Epilepsy & Folic Acid:
        I too would be interested in an update of this topic – I take a folic acid supplement, as I am an epileptic and studies have shown that many anti-epileptic drugs reduce the absorption of folic acid in our bodies, and most epileptics have very low levels of folic acid. I have found, since supplementing, that I have less “brain fog and fewer seizures – now while I can’t prove this, it is not something I want to remove from my supplements bag without much research. I do not know if my diet would give me enough folic acid to compensate for the medications and reduced absorption.

  8. Yes, I’m very curious to hear the Dr’s opinion on the MTHFR research out there. I asked my doc and she just said it’s “controversial”. I have compound heterozygous mutations and was taking methylfolate in very high quantities daily, but recently stopped because I’m wondering if it’s really making a difference. If I don’t need to be spending $40/month on those pills, that would be great!

    1. I recently heard from a physician lecturer that preliminary research suggests *high* doses of methylated B-vitamins (methylcobalamin, methylfolate) may shift the cell reproductive cycle towards cancer formation. He said it’s really just a theory right now, but his current recommendation is to avoid *high* doses of methylated B-vitamins. Those with MTHFR mutations should still take *physiologic* doses of methylated B12 and folate, but avoid high doses.

      I would love to see Dr. Greger do a blog post or video on this issue as I have been unable to find the research the lecturer referenced in making his recommendation and as others have commented, MTHFR mutations are common.

  9. Dr. Ben Lynch and Dr. Amy Yasko have a lot of information on line about the MTHFR genetic defects. Lynch says that those of us with MTHFR defects need to take 5-methyltetrahydrofolic folate. He says not to take the wrong kind – folic acid. Synthetic folic acid is not effective and the unmetabolized folic acid hangs around and reduces our T killer cells leading to immune issues. Also, I believe he says it fills up the folate receptors so the real stuff can’t get in. People can get raw genetic data from 23and me to see if they do have MTHFR (and many other) problems and then go to for help deciphering these very complex genetic issues.

  10. Thanks for your great videos and articles Dr Greger. I mentioned your article on Folic Acid to someone and they said they had read the same studies and the problem with folic acid occurs when little to no vitamin E is ingested. She said that there is no problem with folic acid as long as they take vitamin E as well. Can you look studies again and comment on this. I was considering stopping all folic acid supplementation, but that is not an easy thing to do because nearly all multi-vitamins contain folic acid, not folate.

  11. Hey :),

    nutritional yeast by some brands also contain high doses of folic acid. Which chemical form of folic acid do they contain? Folic acid or the naturally occuring chemical forms of folate? Is nutritional yeast consumption with high doses (or even low doses) of folic acid safe? I have concerns because as far as i know the growing medium of yeast is often fortified with vitamins to achieve such a high content of said vitamins. Therefore my subsequent question is whether the folic acid in yeast is converted into a naturally occuring form.

    Kind regards,

  12. Hello, I have just received my blood test results. As expected urea and creatinine are low because I’m eating only plants. As expected my B12 is low so i will start supplementing this is the reason i went for the test). However, my folic acid is high at 20.5ug/L (the printout states that 3 to 20ug/L is the normal range). Is this a problem or a good thing? Is it merely a healthy side effect of eating a WFPB diet? I couldn’t find the answers to this query on google so if anyone here has some knowledge I’d love to hear it. Thanks, Alan

  13. Should one worry about folic acid in nutritional yeast? How much is too much. The brand I use says is had 270% amount of folate, but lists folic acid at the very end of the ingredient list. It’s Bob’s Red Mill.

  14. Hi Anna,
    b12 supplements often come with folate and b6 because these three B vitamins compliment each other and act as co-factors when being absorbed. As this video states however, the folic acid in a supplement, although may be absorbed is not usable by the body unless we convert it into the usable form with an enzyme. Since folate is abundant in green leafy vegetables I would try to use greens as my primary source of folate.

  15. Possibly the introduction of folic acid into the US food supply to combat birth defects is related to the rise in colorectal cancer seen in younger adults(2/28/17 article in Medscape)

  16. Dr. Greger,

    I moved to a plant-based diet a little over a year ago. Recently I learned that I have an elevated homocysteine level, 14.1 umol/L. I also have a low normal B12 level, 211 pg/mL. My methylmalonate is elevated at 0.6 umol/L. Lastly, my vitamin D is low; 25-HYDROXY is <5 ng/mL. My doctor recommended supplementing B12, Folic Acid and Vitamin D. I'm supplementing as follows:

    Vitamin D : 6,000 IU daily
    B12 : 3,000 mcg weekly

    I haven't started taking Folic Acid supplements. What do you recommend regarding Folic Acid? Also, do you agree with the supplementation above? We will redo these tests in 60 days.

    Any advice is very much appreciated.

    1. Hi Eric, I am one of the dietitian volunteer moderators on this website. I am glad that you had your blood work done and you were given good advice by your dr to improve your B12 level and consequently that will bring your Homocysteine level down to normal. I don’t know what is your daily food intake however, from the high Homocysteine I could guess that sulfur containing protein food that contains methionine which is an essential amino acid(that means it has to be provided by the diet) might have been low. Therefore, given the essential role of methionine in metabolic processes, that means deregulating the transsufuration pathway, increasing homocysteine levels, and methylating homocysteine to make methionine.
      Having said that, Low level of methionine in vegan diet has been indicated to be protective of heart from oxidative damage as well! So, what would one do? The highest containing methionine nut is Brazil nut. I would recommend addition of Brazil nuts may be up to three per day. Other seeds and nuts also have some good percentage in them. I would suggest also keeping a food dairy and seeing a dietitian to assess your daily intake of all nutrients to make sure your food intake is balanced. I hope these explanation are helpful. I shall also ask you to see these below videos by Dr G. and if you needed any more information by all mean enquire in this forum.
      The Okinawa Diet: Living to 100

      Methionine Restriction as a Life-Extension Strategy

      Vitamin B12 Necessary for Arterial Health

    2. Hi Eric,
      I’m one of the medical moderators here on the NF site. A I was formulating my response I noticed that one of our nutritionists also has given you an excellent response from a food based nutritional perspective. I’d like to highlight another factor that may be at play here which you can pursue if you have the resources available to you to do so. It is very likely that you have a genetic variant on a gene known as the MTHFR gene which is responsible in part for a very common and necessary chemical reaction known as methylation. People who carry this genetic variant can be very inefficient at methylation which often leads to B12 and folate deficiency and elevated homocysteine levels among other things. These individuals need to supplement with the methylated forms of these B vitamins in order to bypass the “methylation” step that they are inefficient at. In which case it would mean that you should be supplementing with methylcobalamin (B12) as opposed to another form, and L-Methyl Folate as opposed to folic acid. Your doctor can order the MTHFR blood test to see if you possess the genetic variant and how many copies you have. (You can potentially have a copy from each of your parents and these variants are quite common among the general population) This information would better assist you and your doctor in determining the best and most effective supplementation regimen for you.
      Hopefully this information will be helpful to you.

  17. Can someone please explain to me why OBGYNs refuse to test for Folate, yet recommend Folic Acid? We are on our second OBGYN, and when I’ve asked them to include Folate as part of blood test, they ask “Why”, with an offended look. I explain that my wife and I prefer she get her Folate from food rather than Supplement and we’d like to switch to Fuhrman’s Prenatal, devoid of Folic Acid. They say, a Folate test and results are not going to say anything about whether or not you have enough Folate for your baby. I just want to know my wife’s levels to get a ball park idea of how low or high they are, but both physicians REFUSE to do it. Why is this such a big deal to include in a blood test?? And they won’t include B12 either. Why? What’s the harm?? They don’t even know her levels!?! Wouldn’t they want to know this? So is OK to push Folic Acid on her, but refuse to check levels of the thing you’re pushing?

    1. Casper: I don’t know why, but that kind of refusal sounds criminal to me. My heart goes out to you both.

      You shouldn’t have to do this, but if you want the tests, you can get them on your own. I don’t know which organizations are more credible than others, but the following site was once recommended to me. You basically order your test on-line and then walk into their clinic to get your blood drawn. It’s pretty cool. Walk-In Lab:

      Good luck to you both.

      1. Thanks Thea!

        It’s ok. We’re making sure she gets 150-200% Folate from food per day. And I think a blood test from a year ago showed her levels being ok, before we became really focused on Folate foods specifically.

        They just don’t want to include it. So I wondered if it’s their egos getting in the way, or if there’s a cost-based reason, or medical politics? Strange.

    2. Hello, Casper,

      sorry to hear that. I think maybe they refuse to take the test because it’s too expensive? Maybe it’s not covered by your insurance? Other than money, I don’t think there is any kind of harm. But they may be right – blood levels won’t show exactly the level of folate inside your wife’s cells and tissues (tissue saturation). I think she should do a compromise – take supplement, but don’t take folic acid, take L-5-Methyltetrahydrofolate instead. It’s avaliable as a supplement. Dr. Greger could mention this :)

      Have a nice day!

      Moderator Adam P.

  18. Hello, I am on a low fat plant based diet and my daily meals are:

    Breakfast: always a green smoothie with 3-4 fresh fruits (banana, sweet melon, mango, kiwi and either blueberry, raspberry or strawberry with a handful of either raw spinach or kale and couple of tablespoons of flaxseed meals in my smoothie
    Snack 1: a good handful of mixed raw nuts (walnuts, pecans, almonds, pistachio, hazelnuts) and couple of direst fruits such as apricots or prunes as snack,
    Lunch: Whole wheat and whole grain breads, hummus and mix salads with tomato and cucumber and two to three times a week i also include half of avocado.
    Snack 2: 3 to 4 fresh fruits (watermelon, peaches, nectarine, grapes, orange or mandarin etc..)
    Dinner: A healthy warm dish with different veggies and legumes and good carbs (brown pasta, brown rice etc..)
    an hour before bed: Cup of fresh mint tea or green tea and a small piece of vegan 70% dark chocolate

    I am planning to get pregnant and want to know if I am getting the required folate and iron in my diet or do I have to still take specially folic acid supplements specially during pregnany? I am taking only daily Vitamin D (2,000 IU) and weekly sublingual vitamin B12 (2,500 mcg.

    Thank you.

    1. Good luck.

      I recommend two things:

      1. Download Wholesome app. It’s an amazing micronutrient tracker, and you’ll easily see the Best Food sources of Folate and daily % based on serving size.

      2. Think twice about telling any doctor (unless vegan) about taking a prenatal without Folic Acid. They will make you feel guilty and stupid. They’re robots when it comes to dietary recommendations. They have no idea about the increased risk of Breast and Colorectal cancer created by Folic Acid.


  19. This is a great question for a dietician. Please be careful about listening to advice from anyone without years of education and training. That being said, there is at least one reputable source (if not many) where you can input your food intake and run nutrient reports. It is located here: After you input your food and the amount of food you consume, use the report tab and choose the nutrient report tab.

    Like anything, this report is a guide. Food differs in nutrient content dependent on the soil and many other factors. But it will give you an idea…… and it’s a great place to start.

    If it were me, I would check in with a qualified nutrition professional at least once. I’ll bet there are whole food plant based dieticians out there :) It sounds like you are really on top of things… and I hope the tool I provided helps you. Good luck with your pregnancy!

    1. Alenoosh,

      Again, the point cannot be stressed enough…

      Going to any doctor or dietitian who does not operate out of a WFPB paradigm, is nearly pointless. There are tons of very smart, highly educated doctors out there, like Perlmutter and Davis, and Mercola, and Hyman, et al.. who will tell you animal foods are actually health-promoting.

      So, IMO you’re only safe by following the advice of any of our Plant-Based leaders. If you could find a Plant-Based dietician in your area, expect to pay a serious premium and not have insurance coverage.

      Good luck!

    2. That’s true. Be careful who you listen to in person, or on a thread like this. That includes clowns like me.

      Let’s be clear: FOLATE and CHOLINE are crucial for the development of your precious one, especially in the neural department.

      So, if you don’t think can satisfy your Folate requirements from Food, than I suppose it’s worth taking the daily Folic Acid to be SAFE.

      That is why it’s crucial for you to do your own homework, and continue to eat up as many videos from Dr. Greger in this pre-pregnancy phase.

      I would not (personally) listen to any dietician unless they are certified WFPB and prove to me that they have superior nutrition knowledge than me. Just as I wouldn’t take nutrition advice from a non-vegan doctor. The average dietitian and doctor EATS and pushes Animal foods on people.

      If you only listen to Dr. Greger you’d be in the best hands possible.

      Also, Dr. Fuhrman is also a gem and thankfully sells a Prenatal without Folic Acid which is hard to come by.

      You have to also consider this: Check your Folate levels to see if they look good or not… a lot of people have mutation(s) in MTHFR which will affect your Folate levels.

      Warning: OBGYNs may guilt you into Folic Acid and care not to discuss (simply out of ignorance) how you can successfully get enough Folate from foods. They’ll treat you as if YOU lack the knowledge and make you feel like you’re putting your baby at risk if you try to take some stupid Prenatal (like Fuhrman’s) without the Folic Acid. I’m just preparing you for the world that my wife and I have experienced… I refuse to accept robots telling me what’s good for me.. That’s why I get my knowledge from gems like Dr. Greger.

      So if you find out you have pretty low levels of Folate after a blood test and your surprised because you generally eat lots of greens and beans, asparagus, mango etc… then you may have MTHFR mutation.

      Good luck!


  20. I just want to thank everyone for your helpful tips and advices. Unfortunately I could not find any certifed plant based dietition in my area (I live in Dubai) and I didn’t tell my gynecologist that I am not taking folic acid (she prescribed it 6 months ago) because I know she will be mad at me. I think I will just have to go and do a test to make sure my folate level is ok! finger crossed :)

    1. Alenoosh,

      yes, this dose is safe, but how much exactly should you take depends on why do you want to take it.

      Moderator Adam P.

  21. Dear Dr. Greger,

    I have been taking folic acid 0,4 mg supplements during first 3 month of pregnancy. I would like to know if it can harm me and baby ? If so, what should i do now ? I’m on my 6 month of pregnancy.
    In France, my doctor gave folic acid, iron without check up if i need it or not and told me that iodine is not necessarily, there no proofs that iodine works… He also gave me prenatal vitamins from “SOLGAR”. Please tel me should i take them or stop to take them.. I’m shocked. I hope you understand my worry.
    Thank you so much for your help and your hard work to help the people !!!!!

  22. Hi! I’m approximately 4 weeks pregnant and the prenatals that I’ve been taking don’t have folate or folic acid in them. I’m concerned I may not be getting enough, although I do eat primarily plant based. Can I take a folate supplement to be sure I am getting all the baby needs? Am I correct in thinking a folate supplement is better than folic acid? Or maybe I just need to eat a cup of chickpeas a day?

    1. Hi Andrea! The SuperTracker program through the USDA is still active. If I were concerned, I’d enter three to seven days worth of data and then look for the nutrient tab report. This will tell you approximately how much are getting. All assumptions are approximate, of course, as absorption varies.

      The free program is about to be dismantled, so jump on soon. I was disappointed to learn that our government will not be funding this program in the future, but other reputable free apps might exist as well.
      Meanwhile, Google the SuperTracker app, ignore the first chart and look for the nutrient report tab. Good luck!

    2. Hi I’m a RN and health support volunteer with Thanks for your question and congratulations on the baby. You definitely do want to be sure to get the proper amount of folate. Folic acid is a synthetic form. Folate may be more beneficial in the long run for overall health versus folic acid, but a folic acid supplement will provide what you need for pregnancy.

      You probably haven’t seen an OBGYN this early in your pregnancy, but when you do, I would discuss this with your Dr. The American College of Obstetrics and Gynecology recommend 600mg of folic acid during pregnancy. If you are not able to get that from your diet, then you should supplement. I think most vitamins have the folic acid form and this will prevent your from being deficient which you don’t want to be during pregnancy.

      Good luck to you and the baby.
      The information on is designed to complement, not replace, the relationship between a patient and his/her own physician and is for informational purposes only. The information is not intended to be a substitute for professional medical advice, diagnosis, or treatment. Always seek the advice of your physician or other qualified health providers with any questions you may have regarding a medical condition. Never disregard professional medical advice or delay in seeking it because of something you saw or read on the website.

  23. I see the UK has now endorsed supplementing all flour/bread with folic acid; it’s a shame they remove the choice for people if it is possible to get a better result eating broccoli and spinach.

  24. Thanks for all your videos, you are a life saver.

    However I have a question, does it mean that folic acid should not be taken at all? For example, it is often added to fortified food such as nutritional yeast, is it bad to consume it? (one serving of my nutritional yeast provides 100% of RDI folic acid)

  25. Hello !

    Thank you for the great video !

    I would like one small clarification:
    in the 0:29 of the video, it is shown the top 10 sources of food folate.

    Where can we find this source ?

    I ask because in the section “sources cited” below the video this source does not exist.

    Thank you very much for your time !

  26. It seems quite easy to go over 300% the recommended DRI for Folate by eating natural food such as beans, cauliflower and beets on a Vegan diet. Is that anything to be concerned about?

  27. Hi I’m a RN health support volunteer. Thanks for your great question. Folate is water soluble so the body is not able to store high amounts of it like it can with a fat soluble component. It is not a problem to eat too much folate from natural food sources. You can get too much folic acid in vitamins and processed fortified foods.
    “Yes, you can get too much folic acid, but only from man-made products such as multivitamins and fortified foods, such as breakfast cereals. You can’t get too
    much from foods that naturally contain folate.” US Dept of Health and Human Services.


  28. Hi, my doctor recently recommended I take 1 mg of folic acid a day to help memory issues. I am wondering if there’s any new research on this? I see the video above comparing folic acid and folate was a few years ago.
    Thank you very much.

      1. Thank you.
        May I ask one more question?
        Do you and Dr. Gregor recommend vegan omega -3 supplements?

        Appreciatively, Gail Bumsted

  29. Hello, My internal medicine doctor suggested I take Folic acid and to help with lowering LDL.
    I watched Dr. Greger’s video on this. Apparently we need folate not folic acid.
    Any thoughts?

    Gail Bumsted

  30. Hi Doctor Greger,

    I’ve wanted to ask regarding administer the active form of folate via supplement, namely pills of 5-Methyl Tetrahydrofolate.
    would they be safe and advantageous? or also problematic and cancer triggering like the normal folic acid pills?

    my girlfreind and i planning on get into pregnant and tough we are vegan and try to eat healthy i am afraid she is not getting enough folate in her diet..

    Thanks, Amir R

  31. Amir,

    I’m a firm believer that test don’t guess. I’d encourage you to have you both tested and see if indeed your folate metabolism is optimized.

    The use of the active format, 5-methyl tetahydrofolate is a far superior choice and has a very high safety index. For some references see the European Food Safety paper on two forms: and the NIH’s take at: 5-

    Dr. Alan Kadish moderator for Dr. Greger

  32. Is there any research that I could look at regarding higher than normal blood folate levels in vegans or could one of you good wise people please enlighten me? Some background…my 13 year old daughter have been vegan for 5 years and our blood tests indicate that we both have blood folate levels above the normal range and B12 levels at the low end of the range. We eat mainly soya, berries , nuts, legumes and vegetables daily. We drink fortified plant milks and take no supplements. Our GP is unsure why our blood tests are like this and whether it is healthy or harmful. I’ve been trying to research but to no avail and then it occurred to me that the people responsible for my nutritional ‘bible’ might be able to help.

    1. Al: You mentioned taking no supplements. It is well established that eating a varied diet of whole plant foods is appropriate for people of all stages of life, including children. However, all the experts I follow, including Dr. Greger, agree that a supplement of B12 is essential. B12 supplements are cheap and come in chewables. You can see the specific B12 recommendations here: Maybe your fortified milks cover the need, but it’s worth checking into to make sure. I take a pill just to be safe.

      There also several pages on this website which talk about B12 and explain why a supplement is necessary. (Note: You can get by without a B12 supplement for some time, maybe even years (or in some cases just months), but eventually the lack will catch up to you and cause serious problems.)

      That’s the only firm ground I’m on. I can’t explain why your blood folate numbers seem high. That’s a new one for me. I’m hoping someone else will jump into discuss that one. Note: The current pages get more attention than old pages. You might want to repeat your post (or at least the part about the folate) on the current page so more people will see it?

      Good luck!

      1. Thank you for your reply, much appreciated. I have now bought a B12 spray and have been taking it daily. The doctor was baffled by the high blood folate levels, however, I may have found the reason. I enjoy eating yeast extract and nutritional yeast, and both have high levels of folic acid added. This is the only thing I can think of. The doctor seemed unconcerned and thinks that high blood folate levels shouldn’t be harmful.

        1. Al: Thanks for your reply.

          Your reply gave me one more thought to share: I’m no expert, but I agree that it doesn’t seem worth stressing too much about the folate levels. On the other hand, if the levels become a problem or you just want to see if the nutritional yeast is really the culprit, there is at least one brand of non-fortified nutritional yeast (Sari if I remember correctly) which doesn’t have the added folate. I understand that the non-fortified brands are more expensive, but you could give it a try some time if you were interested.

          Very happy to hear you got that B12. :-) Good luck!

    2. Thea has already given you some good advice about Vitamin B12 and I’d encourage you to review that information and to carefully consider the advice to take a Vitamin B12 supplement. As far as elevated levels of folate, here is one study you may find reassuring: Of course with any abnormal lab values you need to work with your healthcare provider focusing on how much your levels deviate from what’s been determined to be a “high” level and if there seem to be any associated symptoms.
      We’re glad you consider this site a reliable source of information and good for you promoting healthy nutrition for your daughter as well eating well yourself.

      1. Thank your reply. I have replied to Thea’s post above. I really appreciate you taking the time to reply. The link to the study you sent was most useful. I am hoping that the doctor is right and that high blood folate levels are nothing to be concerned about. Many thanks, Al.

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