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The Little Known (But Crucial) Difference Between Folate and Folic Acid


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If I asked you which of these vitamins was found naturally in food, folate or folic acid, would you know the answer? If not, you’re in good company. Medical professionals, nutrition experts, and health practitioners frequently mix up the two, simply because the terms are often used interchangeably.

Many health professionals would even argue that folate and folic acid are essentially the same nutrient. While folic acid is often considered to be a supplemental form of folate, there is an important distinction between these two different compounds. For women past childbearing age, and for men in general, excessive doses of the synthetic form of this nutrient are not necessary, and may even be harmful.

The difference between folate and folic acid?

Folate is a general term for a group of water soluble b-vitamins, and is also known as B9. Folic acid refers to the oxidized synthetic compound used in dietary supplements and food fortification, whereas folate refers to the various tetrahydrofolate derivatives naturally found in food.

The form of folate that can enter the main folate metabolic cycle is tetrahydrofolate (THF). (2) Unlike natural folates, which are metabolized to THF in the mucosa of the small intestine, folic acid undergoes initial reduction and methylation in the liver, where conversion to the THF form requires dihydrofolate reductase.

The low activity of this enzyme in the human liver, combined with a high intake of folic acid, may result in unnatural levels of unmetabolized folic acid entering the systemic circulation.

Several studies have reported the presence of unmetabolized folic acid in the blood following the consumption of folic acid supplements or fortified foods. (3) Human exposure to folic acid was non-existent until its chemical synthesis in 1943, and was introduced as a mandatory food fortification in 1998. (4) Food fortification was deemed mandatory due to overwhelming evidence for the protective effect of folic acid supplementation before conception and during early pregnancy on the development of neural tube defects (NTD) in newborns.

Risks associated with excessive folic acid intake

While the incidence of NTDs in the United States been significantly reduced since folic acid fortification began, there has been concern about the safety of chronic intake of high levels of folic acid from fortified foods, beverages and dietary supplements. (5) One of the major risks associated with excessive intake of folic acid is the development of cancer. (6) In patients with ischemic heart disease in Norway, where there is no folic acid fortification of foods, treatment with folic acid plus vitamin B12 was associated with increased cancer outcomes and all-cause mortality. In the United States, Canada, and Chile, the institution of a folic acid supplementation program was associated with an increased prevalence of colon cancer. (78) A randomized control trial found that that daily supplementation with 1 mg of folic acid was associated with an increased risk of prostate cancer. (9)

Researchers have hypothesized that the excessive consumption of folic acid in fortified foods may be directly related to the increase in cancer rates. Excess folic acid may stimulate the growth of established neoplasms, which can eventually lead to cancer. The presence of unmetabolized folic acid in the blood is associated with decreased natural killer cytotoxicity. (10) Since natural killer cells play a role in tumor cell destruction, this would suggest another way in which excess folic acid might promote existing premalignant and malignant lesions.

A high intake of folic acid might mask detection of vitamin B12 deficiency and lead to a deterioration of central nervous system function in the elderly.

In one study, consumption of folic acid in excess of 400 micrograms per day among older adults resulted in significantly faster rate of cognitive decline than supplement nonusers. (11) Another study found a higher prevalence of both anemia and cognitive impairment in association with high folic acid intake in older adults with a low vitamin B12 status. (12) As vitamin B12 deficiency is a common problem for many older adults, these studies suggest that high folic acid intake could cause serious cognitive consequences in the elderly.

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Folate from natural food sources is best

Despite the risks associated with high levels of folic acid intake, it is well established that adequate folate intake from the consumption of folate-rich foods is essential for health.

Folate aids the complete development of red blood cells, reduces levels of homocysteine in the blood, and supports nervous system function. It is well known for its role in preventing neural tube defects in newborns, so women of childbearing age must be sure to have an adequate intake prior to and during pregnancy.

Excellent sources of dietary folate include vegetables such as romaine lettuce, spinach, asparagus, turnip greens, mustard greens, parsley, collard greens, broccoli, cauliflower, beets, and lentils. (13) Not surprisingly, some of the best food sources of folate are calf’s liver and chicken liver.

You can supplement with folate if your dietary intake is inadequate. Look for products that contain the Metfolin brand, or list “5-methyltetrahydrofolate” or “5-MTHF” on the label. Avoid products that say “folic acid” on the label. Make sure to check your multivitamin because most multis contain folic acid and not folate.

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The Adapt Naturals Core Plus bundle features two products that contain folate. Bio-Avail Multi, a multivitamin/multimineral and phytonutrient blend, contains 680 mcg of the most active form of folate, methyltetrahydrofolate. Bio-Avail Organ contains a blend of five organ meats (live, kidney, heart, pancreas, and spleen), which are among the highest sources of folate in the diet.

Women planning on becoming pregnant should consume between 800 and 1200 mcg of folate per day for several months before the start of pregnancy. Unless you’re consuming chicken or calf’s liver and substantial amounts of leafy greens on a regular basis, it’s difficult to obtain this amount from diet alone. If you’re pregnant or trying to get pregnant, I recommend supplementing with 600-800 mcg of folate per day, depending on your dietary intake. Solgar is a good brand, but there are several others that typically use 5-MTHF including Designs for Health, Thorne, Metabolic Maintenance and Pure Encapsulations.

All other people, such as men and older women, should be able to get plenty of folate in a diet with adequate vegetable consumption, and do not need to supplement.

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Join the conversation

  1. Solgar brand uses Mannitol in their vitamins which is classed as a category C in pregnancy which is quite a concern for me. Can you recommend other brands safe for use in pregnancy.

  2. Due to some health symptoms/concerns lately, I had blood labs to see if my muscle soreness and occasional twitch, nerve issues near my wrists have to do with something in my blood or simply related to Frozen Shoulder. Anyhow the lab only tested Folic acid not Folate. That number F Acid was outside of exceeding norm range. What’s weird is I don’t eat breads, cereals, etc. gluten free corn corn tortillas. What should I take from this number (my #40,0 lab range was 4,6-34.8) and apply to my health/concerns? I also had a low C Peptide level. My homocysteine was normal. I also have gene mutation MTHFR, VDR & COMT.

  3. Hello All,
    Thorne has L 5-methyltetrahydrafolic Acid in their B complexes. Per Chris, anything with folic acid is to be avoided, correct?

  4. I know I’m late coming to the party here, but I just wanted to ask about folate. I take separate B vitamins (rather than a B Complex pill) because I’m more comfortable with the amounts in the separate pills on a daily basis. Some of the B Complex vitamins are so low in doses it practically makes no sense to buy them or take them.

    My folate is from Solgar (800 mcg) but the front of my bottle calls it “as Metafolin”, whereas Chris refers to it as Metfolin. Is there a difference between them?

  5. Chris, I would like to add that excess serum folic acid can also reduce homocysteine below the minimum healthy level of 4 umol/l, leading to insufficiency of glutathione and insufficient free radical scavenging causing cognitive impairment.
    IN reply to Sam, yes, if you have the C677T MTHFR variant you are likely to be low in Vit B12 at the cellular level even if your serum level is OK. Supplement only with methylcobalamin for B12 and methylfolate for folate. Avoid folic acid.

  6. Chris,

    What about people who have MTHFR mutation, would the food consumption be sufficient, or you’re forced to supplement?

    Also, are there any plant/meat sources of the active form of folate?

  7. Hi I have been suffering with my stomach/bal for years now a nutritionist has confirmed I have many food tolerances but funnily enough most of the foods have folic acid in them.. I can’t eat any dairy, no fruit or cereals.. I now am anemic for folate & they have given me folic acid tablets 1 per day 5mg I am so ill with them I thought at one point my stomach or bal was going to burst.. I have stopped taking them but I am now getting pains in my feet & arms & I know it’s all connected the doctors will not listen to me that I can not take these folic acid I really need help Is there anything else I can take as these are doing me more harm than good.. I have even been tested on these tablets & it come back I was highly intolerant to them.. I really need some advise because the doctors don’t know what they are doing..

    • Im no expert but it sounds like you may have a B12 deficiency as well. B9 is also known as folate or folic acid. Folate is natural, folic acid is not. The terms are used interchangeably. But they are not really interchangeable. Do some quick research on the difference and you will understand. Anyway, taking folic acid(especially to much) can give false indications as to your B12 levels, which is serious. Just a thought.

    • Tammy, do not take folic acid. Use 5-MTHF folate. Also get your serum folic acid checked – it is likely to be off the charts high and that is bad. It would probably be a good idea also to get your MTHFR gene variants checked, because if you have the C677T allele you can be low on Vit b12 even if your serum B12 is OK. If so use methylcobalamin, not cyanocobalamin as a supplement.

  8. What’s the difference between the Metfolin brand (“5-methyltetrahydrofolate” or “5-MTHF) and the Quatrefolic brand ((6S)-5-methyltetrahydrofolic acid”)?

  9. what can you take against the high dose folic acid in the blood caused by the synthetic supplements ?
    is there something that can remove/metabolise it quickly out of the body ? can tinnitus be a reaction of very high folic acid levels in the blood ?

    • Gil, if you are developing neurological symptoms after large doses of b9, get your b12 checked. B12 and b9 are cofactors in some ways, and it is thought too much b9 may possibly worsen an underlying b12 deficiency.

      Even if you are taking oral b12, it may not be absorbing. Get all your other b vitamins checked too.

      As for the high b9, some people use niacin, but that seems dubious to me. I have no idea if it’s valid.

      • Hi Ann . When I eat folic acid foods i feel having low blood pressure and when I tried to have b12 tablets or sublingual I couldn’t absorb it. So should I rather try taking metfolin . Please let me know

        • Hi Nitish! I used to take a simple B-12 supplement, but I recently switched to a “Superior form” of B-12 called Methylcobalmin (Methyl 12) and I can really feel the difference in my energy levels and work performance. I follow it with 800 mcg of Methylfolate (5-MTHF) not folic acid. I purchased mine at a Whole Foods type of Store called “Sprouts”

            • Hi Nitish,

              FYI, I am a different Ann.

              I take Methylcobalamin sublingual, but I take at least 30,000 mcg a day. If you have trouble absorbing, maybe you are not taking enough, or maybe you are not holding it under your tongue long enough.

              Also, how do you know you are not absorbing?

              Chris has a B12 page.

    • You have to quit your favorite multiple and tell your company why and look for supplements that has folate and avoid folic acid like the plague. This is a hard thing to do. I switched to nutritional yeast for my b complex, plus still having to buy some of those B’s separately, but I can’t get a good B 100 with all natural forms. So far it doesn’t exist.
      The only way to clear out folic acid is avoidance.

  10. Hi, it’s really nice to be in contact with you.

    I hope you can write me back!

    I really need to know if a woman in good health, 38 years old, with good nutrition and living her first month of pregnancy, should take Solgar – Folate 800 mcg (as Metafolin ) Tablets 100.

    I don’t understand if Folate is the same as Metafolin.

    Thanks yo so much!

    I’ll be waiting!


  11. Hi there, love your website Chris Kresser and team, and thank you for the informative article on the little known difference between folate and folic acid.
    I have a 5 year old daughter Elizabeth who was diagnosed with Hereditary Spherocytosis on Christmas Day 2014 and upon diagnosis was prescribed 2 x Folic Acid Tablets 0.5mg which she takes daily, for the rest of her life. Folic acid supplementation is indicated to prevent megaloblastic crisis. Is there a better way to supplement her Folate, rather than using the synthetic folic acid? She’s not a huge lover of greens at this point in time!… By the way, just downloaded your Better than Paleo Cookbook and it looks fabulous! Will definitely start cooking from this. Thanks in advance for your reply.
    Kind regards,

    • Lara, is your daughter treated adequately? Why are you searching for a better way? Don’t worry about the hype of folic acid vs. methylfolate. Know that for some people, methylfolate has incredibly severe adverse effects. Some of us switch back to folic acid after suffering from methylfolate. If it ain’t broke don’t fix it.

      • Yes, she is definitely treated adequately. I just had no idea that there were different forms of folate available and was interested to learn more. Thanks for your reply.

      • I’ve never tried methylfolate but have never noticed problems with folic acid. I’m compound heterozygous for the MTHFR variant and am currently taking a B complex with both folic acid and cyanocobalamin. It seems to be working well so far.

  12. I am taking methyl Cpg. The folate is called methyltetrahydrofolic acid glucosamine salt. Does that mean there is sodium in it?

    • No sodium in that. FYI A salt by chemical names just means a metal combined. Like, Magnesum Sulfate is a salt but it also has no sodium. Magnesium and sodium are metals in the periodic table!

      • Hi I am not able to absorb folate foods . I tried taking sublingual b12 , b12 tablets but couldn’t absorb it either . Can metfolin work for me .Please let me know

        • Nitish, you keep saying you “can’t absorb.” How do you know that? Are you certain of that statement?

  13. If folic acid has been linked with cancer or cognitive decline and folate is obviously the better choice why is the government continuing to make mandatory the addition of folic acid to all flours in the US since 1998. Could this be related to increase of alzheimers as well.

    • Usually the government has some type of political reason, obviously. For example, the “science” behind putting fluoride in drinking water. That is simply a lie. Fluoride is VERY DAMAGING to humans in any quantity. Do some research. An industry had a need to get rid of its fluoride and “convinced” the government to dump it in drinking water. Don’t be so naive please.

    • Hey Chris! I have MTHFR and if you get your greens and veggies in, you should be good, but knowing which foods have folate is essential.

      MyKind has vitamins for men and women from real food sources and I’d recommend them. There are countless vitamin makers that use L5-Methylfolate and a lot of people to well with those. They are pretty inexpensive too!

  14. Hi, thanks for the article! I have a question about your ur suggested folate intake for women planning on gettiNg pregnant. Is that the same for a woman who is homozygous MTHFR t677t?

  15. I am compound heterozygous for MTHFR. I stopped synthetic folic acid 3 months ago and switched to methylfolate (400mcg/day). My MMA and homocysteine levels are good but my serum folate levels are still way above normal. Why haven’t they gone down at this point?

    • It’s possible that the lab being used tests for folic acid instead of folate. Find out what they are doing.

    • Agreed, you probably have a ton of unmetabolized folic acid causing the high reading. The medical fields are not yet caught up between the difference of folic acid and folate.

      I do believe that niacin helps (don’t use the non flushing kind because it is hard on the body. Take regular niacin on a full stomach to avoid the flushing).

    • Again, you haven’t defined what you mean by “causes of both.” How can anyone reply to an incomplete question?