Folic acid

*Consult your doctor before making any changes in your dietary intake related to folic acid. This article is for informational purposes only and not a substitute for medical advice.

Nowadays, many people have issues such as fatigue, irritability, brain fog, anxiety, insomnia and other aches and pains without an apparent cause. Some might think that genetic disorders are the obvious cause. There are many minor genetic differences that influence the way we look and can cause many health problems.

MTHFR stands for methylenetetrahydrofolate reductase. MTHFR is the enzyme that breaks down folic acid by adding a methyl group to it. MTHFR physicians say that if you have a MTHFR gene mutation then you should stop consuming folic acid and replace it with its active form, Methylfolate. Our bodies can’t process excess folic-acid and it is stored as toxins in our organs and tissues. MTHFR practitioners say that the human body needs to convert folic acid into a form of folate that the body can use. The human body, without the MTHFR enzyme, can’t convert folic acid into methylfolate and it builds up in the body as endogenous toxins. As a part of MTHFR gene mutation treatment, you should avoid consuming folic acid or the products that contain it and replace it with methylfolate. Do so only under the guidance of a MTHFR physician.

MTHFR doctors warn people with low activity of MTHFR enzyme that it may cause elevated homocysteine levels. Homocysteine is an amino acid that could be inflammatory. Homocysteine is directly related to cardiovascular disease.

Treatment for MTHFR includes avoiding sources of non-metabolized folic acid which may cause other health problems that might not develop for years. Replace folic acid with methylfolate. An increase in the level of non-metabolized folic acid may also decrease natural killer cell cytotoxicity and weaken the body from fighting arthritis, cancer and anti-malarial drugs.

In older people who have B12 deficiencies, folic acid can cause cognitive impairment and anemia but methylfolate will not. Folate and Folic Acid have the capacity to fight against many cancers but an excess of Folate/Folic Acid can accelerate the growth of tumors that are already present in the body. The degree to which the body doesn’t activate folic acid to methylfolate increases your susceptibility to allergic responses and can also cause blood clots, strokes, anxiety, depression, high blood pressure, migraines and more.

Many thyroid issues have been associated with having a MTHFR mutation problem as thyroid hormones must be activated within the nucleous of each cell and it depends on methylation for this activiation. As part of a treatment for MTHFR gene mutation, women with a positive MTHFR status should consult a MTHFR doctor during pregnancy. MTHFR practitioners also encourage pregnant women to check their MTHFR mutations and suggest that they consume appropriate levels of methylfolate instead of folic acid.

Without knowing the genetics and exposure to toxins, it is better to follow the advice of MTHFR physicians and start the intake of activated folate instead of folic-acid. As a part of treatment for MTHFR, you should consume plenty of organic green leafy greens as they contain good quantity of folates. Eat more broccoli and spinach, and always shop organic. MTHFR gene mutation treatment also includes checking B complex and multi-vitamins to make sure the label says methylfolate and not folic acid.

For the naysayers who think this is all rubbish look at the prescribed drug for folic acid deficiency, Deplin’s active ingredient is L-Methylfolate and not folic-acid. The scientists know the choice to use, so when supplement companies use folic acid it is because it is cheaper, not better.

MTHFR gene mutation treatment can help those with MTHFR mutation to reduce their risk of health problems. Find out if you have a mutation by ordering a home test kit now. Also consider supplements for MTHFR mutations.

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27 thoughts on “Folic Acid – Why You Should Avoid it With a MTHFR Mutation”

  1. I was just diagnosed with the heterozygous C677T and A1298C variant. My dr told me to start off by cutting out all foods enriched with folic acid for two weeks and then we would go from there. This is all so confusing. It’s my understanding that my enzyme functions are working at 65%. Does that mean that my body IS able to change the folic acid to the active folate but only at 65% instead of 100%? What happens if I keep eating foods with folic acid? Can that hurt me? Should I cut out food with folic acid or can I still eat it and just take a supplement. I’m so confused. There are a thousand websites covering this topic and they all say something different. Some say to cut it out altogether, some say its ok to eat it, some say to take a supplement, some say to not start a supplement until you get other issues taken care of. I just found out about this gene mutation a week ago and I’m already over it! HELP PLEASE!!

  2. I would like clarification of the following statement in the article: “An increase in the level of folic acid may also decrease natural killer cell cytotoxicity and weaken the body from fighting arthritis, cancer and anti-malarial drugs.” Does this mean that taking folic acid prevents the anti-malarial drugs from working or that taking folic acid causes the body to weaken from/after being exposed to anti-malarial drugs (just like it weakens the body to have to fight arthritis and cancer)?? This is important to understand since many have proposed that use of Cloroquinolone helps fight Covid-19 infections. Is it that the drug might actually cause a person with MTHFR to lose the battle with Covid if they are also mistakenly taking the wrong folic acid and cannot utilize it properly?

    1. Dee,
      The article refers to unmetabolized folic acid. I will make the edit to make it more clear. This is another reason a person with MTHFR mutation should only take a methylated form of folate.

      1. I’m have one each of the variants. When my blood tests were showing too much B12 in my bloodstream, but symptoms of too little in my methylation cycle, my naturopath concluded that Folic acid was the issue. I stopped cold turkey any enriched food whatever. Switch to organic. You keep using the phrase “unmetabolized folic acid,” Dr. Miranda. Most of your readers would better understand “stay away from ‘enriched’ or ‘synthetic’ additives.” Especially emphasize bread and flour. We’re brought up believing that Wonder Bread with its 12 ENRICHED additives is the only thing that’s keeping us healthy, and here I was, being poisoned with every bite.

        1. Thanks for sharing your view. So true! Yes, I wish that when discussing MTHFR, it would be emphasized that we must truly avoid the enriched foods because they are enriched with synethetic Folic Acid which our bodies can not utilize and actually stores in our body and hurts out body. Once I remove enriched foods and grains, I feel such much better.

  3. my daughter has both MTHFR gene mutations. She started on methotrexate and folic acid for sjia (juvenile arthritis). Now I’m concerned about her taking the folic acid.. her rheumy assured me it was safe because the methotrexate depletes the body of folic acid.. I don’t know what to do. Should I see an endocronologist? She’s only nine..

  4. Folic acid seems to be fortified in a lot of foods.
    Should someone with MTHFR gene avoid everything with it or just limit ? Also how long does it stay in the bloodstream and how long does it take one to feel after eliminating folic acid for diet ?

    1. The amount of folic acid in fortified foods is minimal so you don’t need to worry about it. When considering supplements is a different story, a person with any MTHFR mutation should avoid supplements containing folic acid and instead they should take supplements containing a methylated form of folate. The amount of time that is stays in the bloodstream depends on how fast the person’s metabolism is. A good methylation support formula is

    2. I think they should avoid all the enriched foods because folic acid is like a poison to those with MTHFR. After all, we want our best health so that we can feel our best not just get by or survive.

  5. Dear Veronica,

    Taking folic acid is better then not taking anything at all when comes to pregnancy, however L-Methylfolate is a more suitable format for MTHFR patients. To be on the safe side you should consult with a methylation expert. We have a directory of practitioners that can better help you with this issue. You should know how much to take also which varies depending on your MTHFR mutation and your serum folate levels.

  6. Veronica Brewer

    While pregnant with my son they found spina bifida at the 20 week checkup and found mtfhr after testing me. They told me that it was because of needing more folic acid and baby aspirin. He gave me a prescription for a folic acid supplement and told me to take over the counter folic acid and a vitamin. So I have been taking these for 7 years. The maternal fetal doctor told me to take them for the rest of my life or at least until I am not able to have more children. They told me that it was why my son is so healthy and able to run and play. So this article confuses me because all of the information is different from what they told me. What should I do?

  7. I was taking folic acid for 6 months before getting pregnant then switched to pregnacare once I was pregnant. At my 12 week scan last week we found no fetal heart beat and baby had stopped growing at 8+4. We are obviously devastated and looking for answers we probably won’t ever find. I have hypothyroidism and take 100mg levothyroxine daily. Is this potentially an indicator of MTHFR? Or does it not work like that?

    1. We are sorry to hear about your loss.
      Pregnacare has folic acid and not methylfolate. Although there have been studies showing a connection between hypothyroidism and MTHFR mutations, being hypothyroid does not automatically guarantees you have a mutation. The first step is to get tested. We recommend either or Once you have their results you may come back to this site and select the Methylation report under DNA Reports.

    1. Not necessarily. There are other factors that affect homocysteine levels. For example; you may also have a mutation on a CBS gene that is an up regulator that will counter the MTHFR mutation bringing homocysteine levels down. In this case despite your homocysteine levels being down other aspects of the methylation cycle may not be optimal so homocysteine is only one marker to look out for. There are also other epigenetic factors that will affect homocysteine levels.
      If you have a mutation on MTHFR you must always look at your folate levels. Please read the following article:
      We also advise you to get guidance from one of the healthcare practitioners listed in our directory to make sure you get the right advice.

  8. Dear Joyce,

    We cannot give you medical advice in here, however you should get tested for MTHFR to determine if your body can metabolize Folic Acid. You should also consult with one of the doctors in our directory to get coaching on exactly how much to take and what else you might need.

  9. I have gotten blood clots and they have done thorough blood tests and told me to take Folic acid 1000 mil and B-100 complex vitamins because my hymoglisteen was high an I have lupus anticoagulants at 112. Should I be taking these ?? I have 4 blood clots in my right leg 2 in my main artery

  10. I suffer from psoriatic arthritis and Iam on methotrexate once a week I have been advised too take folic acid , would you advice not taking the folic acid ?

    1. Dear Elaine and Linda,

      For the most part it is better to take Methylfolate rather than folic acid, however what we recommend is for you to consult with a practitioner that is experienced in the subject to evaluate your condition and determine what you should be taking and how much. Please check our directory at

      1. I’ve just finished 5 months of MTX chemotherapy for Choriocarcinoma, I was given Folinic Acid as a recovery and told that folic acid doesn’t help…confusing when so many are told to take it when they are on a low weekly dose of MTX for AI diseases ?

      2. Susan Easterday

        I was on Methotrexate and the Folic Acid. I developed Felty’s Syndrome and lost my immunity. I do not know if it had anything to do with th MTFHR as I was diagnosed with it until last year, six years after developing the Felty’s. I am Homozygous for MTFHR. I am now on Deplin.

        1. Deplin is definitely a better choice than folic acid, however Deplin comes in 5mg to 15mg which when taken long term could through your body into over-methylation. You should check your serum folate levels and consult with a physician that specializes in MTHFR to help you get on the right dosage long term.

    2. My daughter and grandson were tested and have MTHFR and assume I do too. I am deficient in pantothenic acid and borderline in B12 and Folate. I am about to take hydroxycobalamin B12, but with it would you recommend methylfolate or can folinic acid be taken instead? I am concerned about taking anything that could cause palpitations or anxiety. Thank you.

      1. You can definitely try folinic acid. If you don’t feel good just stop. Folinic acid acts more on building DNA while methylfolate on methylation.

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