What Is a MTHFR Mutation?

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What is an MTHFR gene mutation
Wellness Mama » Blog » Health » What Is a MTHFR Mutation?

When you have an autoimmune disease like I do, you get to learn a whole new language when it comes to your health. Terms like TSH, flare, leaky gut, and triggers become part of your vocabulary. One term that I’ve gotten many questions about lately and that deserves the attention it is finally getting is the MTHFR mutation.

What Is MTHFR?

MTHFR is an enzyme that adds a methyl group to folic acid to make it usable by the body. The MTHFR gene produces this enzyme that is necessary for properly using vitamin B9. This enzyme is also important for converting homocysteine into methionine, which the body needs for proper metabolism and muscle growth and which is needed for glutathione creation . The process of methylation also involves the enzyme from the MTHFR gene, so those with a mutation may have trouble effectively eliminating toxins from the body.

The genetics home reference offers more detail:

The MTHFR gene provides instructions for making an enzyme called methylenetetrahydrofolate reductase. This enzyme plays a role in processing amino acids, the building blocks of proteins. Methylenetetrahydrofolate reductase is important for a chemical reaction involving forms of the vitamin folate (also called vitamin B9). Specifically, this enzyme converts a molecule called 5,10-methylenetetrahydrofolate to a molecule called 5-methyltetrahydrofolate. This reaction is required for the multistep process that converts the amino acid homocysteine to another amino acid, methionine. The body uses methionine to make proteins and other important compounds.

Contrary to how it looks, “MTHFR” is not an abbreviation for a popular curse word, but a shortened form of methylenetetrahydrofolate reductase… Aren’t you glad it is abbreviated?

I touched on the importance of the MTHFR enzyme briefly in my post about folic acid vs. folate and why I am careful to avoid synthetic folic acid in supplements and foods.

Those of us with a MTHFR gene mutation have a highly reduced ability to convert folic acid or even folate into a usable form. Research estimates that as much as half of the population may have an MTHFR gene mutation, though there are many variations of the mutation, depending on how the gene was passed down from the parents. More on that below.

Problems From an MTHFR Gene Mutation

Dr. Izabella Wentz explains how the MTHFR mutation can affect those who have it:

Individuals with low activity of the MTHFR enzyme may present with elevated homocysteine levels, which have been associated with inflammation and heart disease, birth defects, difficult pregnancies, and potentially an impaired ability to detoxify.

Nutrient deficiencies in Folate, B6 and B12 have been associated with elevated homocysteine.

Individuals with the MTHFR gene actually have a difficult time processing folic acid that is present in most cheap supplements and added to processed foods. Some professionals claim that this type of folic acid may even cause a build-up in the body leading to toxicity. Studies have been done that showed folic acid supplements increased cancer risk… one more reason to ditch processed foods and your multivitamin!

Some naturopathic doctors like Dr. Doni Wilson suspect that lingering fatigue, fogginess, anxiety, sleep issues and inability to deal with alcohol and other toxins effectively can be a result of an underlying gene mutation like the MTHFR mutation. She explains how this affects many aspects of health and how stress is a compounding factor:

Activated folate (named 5MTHF) goes on to give its methyl group to other nutrients and substances – a process called “methylation.” It is required for the creation of every cell in your body, so if it is not activated properly, you can imagine what a significant issue it would be. 5MTHF, along with several other nutrients, is also used to create and process neurotransmitters (messengers in the nervous system like serotonin, epinephrine, norepinephrine, and dopamine); create immune cells and process hormones (such as estrogen); as well as to produce energy and detoxify chemicals.

Stress, in all its forms, inhibits this “methylation” – the transfer of methyl from 5MTHF to other substances. So when you are under stress, it is especially important to provide the nutrients necessary for these processes.

To clarify in more detail, the liver is a major processing system, involving countless enzyme pathways, including methylation, which turn one nutrient into another and toxins into non-toxins, preparing them all to be used and/or expelled by the body. When you drink alcohol, it is your livers job to process it using methylation, but if your nutrients are depleted or you are stressed, your liver will not be able to complete the process effectively, leading to symptoms associated with a hangover.

Identifying a potential MTHFR defect is especially important for women of childbearing age, as this defect can increase the risk of many problems in an unborn child, including folate related disorders like Spina Bifida.

Types of MTHFR Mutation

There are many different possibilities when it comes to MTHFR gene mutations and science is still working to understand them all. I’ve included links to more in-depth resources below, but there are several common mutations that can occur.

The reason for all the types of mutations is variations in the specific genes passed on from each parent. In other words, if both parents pass on a healthy gene, a person won’t have a mutation at all. If one parent passes on a healthy gene but the other passes on a mutated gene, several variations can occur. If both parents pass on a mutated form, there are many more scenarios that can occur.

The two most problematic mutations that can occur are  C677T and A1298C, which denote the placement of the mutation on the gene. The most common forms of MTHFR mutation involve various combinations of these genes being passed on from each parent:

  • Homozygous: the same gene passed on from both parents-  can occur if both pass on the 677 mutation, or the 1298 mutation.
  • Heterozygous: one parent passed on the 677 mutation or the 1298 mutation but the other parent passed on a normal gene.
  • Compound Heterozygous: one parent passed on the 677 mutation and the other passed on the 1298 mutation.
  • Other more advanced and rare mutations.

What Happens When the MTHFR Gene Is Defective?

Those with a defective MTHFR gene have an impaired ability to produce the MTHFR enzyme (estimates range from 20%-70% or more). This can make it more difficult to break down and eliminate not only synthetic folic acid but other substances like heavy metals.

Since folic acid can’t be converted into the usable form, it can build up in the body, which can raise levels of homocysteine. High homocysteine levels are associated with a higher risk in cardiovascular disease. This also affects the conversion to glutathione, which the body needs to remove waste and which is a potent antioxidant.

In short, we are just learning the extent to which this can affect health, but there is strong evidence that because of the affect on methylation, it can increase cancer risk, cardiovascular disease risk, risk of fetal development problems and more. It can also possibly contribute to or exacerbate other problems like autoimmune disease, mental issues and more.

Dr. Ben Lynch of MTHFR.net has a comprehensive list of conditions he has been able to link to a MTHFR gene defect.

How to Get Tested for MTHFR Gene Defects

Though there are many symptoms that can be associated with an MTHFR defect, the symptoms can vary widely from person to person and only a test (blood or saliva) can verify a gene defect and the type.

Janie at Stop the Thyroid Madness compiled a great list of ways to get tested. Local doctors are able to run these tests as well, but not all doctors are well-versed in handing MTHFR issues…

Dr. Amy Yasko will test about 30 methylation SNP’s (single nucleotide polymorphisms)here. You may need a doctor’s prescription. It is considered to be a highly accurate test.

A similar one you can do on your own with saliva…and is highly recommended and popular…is from 23andme. It is stated to miss 5 SNP’s that Yasko’s will not miss, but is cheaper and still an excellent test. NOTE: 23andme states the following:

23andmeprovides ancestry-related genetic reports and uninterpreted raw genetic data. We no longer offer our health-related genetic reports. That does NOT mean you won’t get what you need. After the 23andme results come back, you’ll get “raw data”. You will upload that data to any of the following, which in turn will give you what you need:

  • Genetic Genie, which will look at your methylation genetics just by reading your 23andMe raw data.
  • Live Wello, which gives a great deal of information to you based on 23and me, plus links to learn more about each gene’s potential problem.
  • Nutrahacker will tell you what supplements you need to take, and which ones plus more you need to avoid, due to your mutations. It’s very interesting!
  • Sterling Hill’s app mthfrsupport.com/sterlings-app or you can contact her and pay for a call to help with interpretation of your genetics.

A VAST amount of genetic information can be obtained from Promethease.com

Here’s a good string about testing methyl pathways vs genome testing.

I personally have experience with Spectra Cell tests.


Though it isn’t possible to change a gene, there are things that can be done to minimize the potential for problems or to help avoid problems in children (before and during the mother’s pregnancy). As I said, the research is still developing on this, but some things that I find personally helpful are:

  • Focusing on gut health: Especially when the body has impaired ability to use certain nutrients, it is important to focus on gut health so that the body can absorb the nutrients from food as effectively as possible. I personally avoid antibacterial soaps, vegetable oils, processed grains and refined sugars and support my gut with fermented foods and homemade broth. This also helps avoid candida, which can make MTHFR related problems worse.
  • Avoiding environmental toxins as much as possible: Those with an MTHFR gene defect have an impaired ability to eliminate toxins. I avoid plastics, chemicals in beauty supplies and cleaning products, and scented candles, which can all release harmful chemicals. We use houseplants and other methods of cleaning our indoor air, and filter our drinking and shower water.
  • Not taking anything with Folic Acid: As I explained in this post, folic acid is the synthetic form of folate that cannot be used by those with a MTHFR defect and which can be very toxic. I avoid any supplements with folic acid and only take L-MTHF forms, which are the methylated forms that my body can use. I also take a methyl-B12 which is supposed to help the body use L-MTHF.
  • Lots of Leafy Greens: According to Dr. Ben Lynch, dark leafy greens contain the methylated forms of folate that those with a gene defect need. As if we needed more reasons that it is important to consume green veggies… I try to work in green veggies at every meal.
  • Avoid Processed Foods: Again, as if anyone needed another reason to avoid processed foods… Many processed foods have synthetic folic acid added.
  • Avoiding things that can block or deplete folate levels: Certain medications, including hormonal contraceptives can interfere with folate levels, and medicines like antacids can interfere with B-12 absorption.
  • Avoiding Heavy Metals: Heavy metals in diet or environment are harder to remove from the body for those with a gene defect, so I’m careful to avoid these.
  • Help a Body Out: Since those with a MTHFR defect have an impaired ability to eliminate toxins, I do things to help support my body in this process, such as: detox baths, sauna use, drinking enough water, dry brushing my skin and exercise (sweating). I also do strange things like using detox mud shampoo, detoxing my pits, and foot soaks.


This video with Dr. Alan Christianson and Dr. Ben Lynch provides lot of detail about MTHFR and how it affects health.

Additional Resources

If you are new to MTHFR and feel overwhelmed like I did, here are some great resources:

Have you ever been tested for MTHFR? Please share your experience to help others!

This article was medically reviewed by Dr. Scott Soerries, MD, Family Physician and Medical Director of SteadyMD. As always, this is not personal medical advice and we recommend that you talk with your doctor.

An MTHFR gene mutation affects the body's ability to use folic acid or folate & increases risk of disease. Learn how to know if you have it and what to do.
Katie Wells Avatar

About Katie Wells

Katie Wells, CTNC, MCHC, Founder of Wellness Mama and Co-founder of Wellnesse, has a background in research, journalism, and nutrition. As a mom of six, she turned to research and took health into her own hands to find answers to her health problems. WellnessMama.com is the culmination of her thousands of hours of research and all posts are medically reviewed and verified by the Wellness Mama research team. Katie is also the author of the bestselling books The Wellness Mama Cookbook and The Wellness Mama 5-Step Lifestyle Detox.


222 responses to “What Is a MTHFR Mutation?”

  1. Jennifer Avatar

    I can’t see the dates, but can anyone recommend DNA ‘INTERPRETED’ testing? 23andme is not for me. Anyone do Dr.Amy’s? Thoughts? Thanks much

  2. Dave Avatar

    Hi – here’s what 23andMe says about it: https://blog.23andme.com/health-traits/our-take-on-the-mthfr-gene/

    “Based on the existing data, scientists at 23andMe have concluded that people should not interpret their genotypes at the common MTHFR variants as having an effect on their health. In order for a connection between a genetic variant and a health condition to be considered real and clinically meaningful, well-run scientific studies need to show convincing and consistent evidence for that association. As statements from multiple scientific and medical organizations indicate, that is currently not the case for the common MTHFR variants.”

  3. Dietra Avatar

    Hello, I am wondering what I can do for a two year old that possibly has this mutation…

    How much methyl B12 and Folate can I give him…?

  4. Stephanie Reamer Avatar
    Stephanie Reamer

    Thank you so very much. Hasimatos 2diagnosed 26 years. On Nature-throid rather than synthetic t-4…all the difference! Yet, this tells a person Why this crazy thing may occur.

  5. Kirsten McCue Avatar
    Kirsten McCue

    Very interesting. I would like to be kept in the email loop of any upcoming info on this gene as I was tested positive with it as was my son. I was told to take Deplin is this good idea or bad?

  6. Erwin Alber Avatar
    Erwin Alber

    It is in my opinion particularly important to avoid vaccines of any kind if one or one’s child has the MTHFR mutation, in order to avoid heavy metals such as the mercury or aluminum in vaccines, due to the body’s inability or difficulty to detox. Children with the MTHFR mutation are particularly susceptible to autism.

    I am however a strong advocate of avoiding vaccines of any kind altogether regardless of the presence or absence of the MTHFR mutation, because as far as I am concerned vaccines cause far more harm including deaths than the diseases they are used against. If one wants to vaccinate, at least one should make sure to get the child tested first to make sure it doesn’t have the MTHFR mutation.

  7. Jeanine Avatar

    Unfortunately, 23and me does NOT do MTHFR testing anymore!!! Don’t know where to go to get this testing done at any reasonable price.

  8. Vera Avatar

    My son has this also his Dr has him on methyl-guard plus by thorn what do you think of this supplement
    Please let me kmow. Thanks

  9. Eric Potter Avatar
    Eric Potter

    As a physician caring for MTHFR patients, I am asked this question repeatedly regarding “natural vitamins”. Since I am not your doctor, I cannot answer this question definitively for you, but… here are some general pointers I explain to patients.

    1) Natural vitamins like Garden of Life are generally good. They cannot state that they contain “methyl folate” or “folinic acid” but if they do not state “folic acid”, then you can assume that they are safe in terms of what you are getting. The “natural folates” would be similar to what you are getting in green leafy veggies.

    2) The question becomes, are the “natural folates” enough? Without knowing a person’s MTHFR status plus other genes in their methylation cycle and without functional labs for folate or B12 deficiency (not just levels of the vitamins themselves), I cannot guarantee any vitamin, natural or synthetic, is “enough”.

    3) So should one just aim for a little too much? Maybe, maybe not. Many people, even with MTHFR 677, can overmethylate and have negative symptoms (headaches, insomnia, jittery, anxiety, teeth grinding, etc.). I always recommend adding in methylfolate or folinic acid at no more than 200-250mcg daily in the beginning, slowly increasing till we determine that enough is enough.

    I know this only answers half the question… Garden of Life is likely safe to continue. The other half of whether or not you need more is not answerable by the information provided.

    I hope this helps. Blessings…

  10. Cara Avatar

    Hello, I am 4 weeks pregnant with my 5th child, I recently lost my 4th child, she was stillborn at 24 weeks. All my other pregnancies were normal and healthy. I have been reading your article about the MTHFR gene mutation. I have been taking folic acid in a pregnancy multivitamin called garden of life raw. It isnt synthetic but made from raw organic food and herbs. I have just now ordered folinic acid after reading this but should I stop taking this mutltivitamin or take them both (the folinic and folic acid) i’m not sure what to do?? Thanks for your help

  11. Amnesia Avatar

    This is incredibly helpful just now navigating heart issues that I just found out are MTHFR related. Thank you for sharing this compendium of knowledge and self care!

  12. Teryn Watts Avatar
    Teryn Watts

    Katie, I know this post has been out for a while, but I have been waiting to take the test because of this very problem https://techcrunch.com/2017/09/09/23andmes-second-act-sits-squarely-in-drug-research-and-development/ i figured you would want to know since you have been sending people there. I did get another company from a friend of mine https://myhomemthfrtesting.com/ they destroy the samples after the test so no shady business.
    Thank you for everything you do

  13. Ricki Avatar

    Is anyone concerned about the toxins carried through animals into all animal products (meat, milk, eggs)? From what I understand, they can’t release pollution from where and what they are eating and so it goes straight into us when we consume animal products. Maybe at higher rates than the air we breathe and the soaps and lotions we use. If we avoid using antibacterial soap, perhaps we also should consider not eating animal products that have been given antibiotics all through their lives. I don’t want to come across as preaching… but I can’t help but chime in if I think it might really help someone, and hopefully simplify the road to wellness too!

  14. Debora Barnes-Josiah Avatar
    Debora Barnes-Josiah

    “Ditching your multivitamin” is not responsible advice. The NIH estimates that 25% of Hispanics and 10-15% of non-Hispanic Caucasians have two copies of the mutation. Prevalences may vary for ethnic groups not as common in the U.S. Regardless, unless otherwise indicated folic acid supplementation is an essential part of a healthy diet pre- and during pregnancy. Promoting all-natural vitamins is fine, but discouraging the use of others is harmful. As a Maternal and Child Health epidemiologist, I see many more cases of newborns affected with neural tube defects than by maternal MTHFR.

    1. Katie - Wellness Mama Avatar

      Agreed that supplementation is important, but I would still say that in a multivitamin, it is beneficial to choose a natural form like folate or methylfolate. These are easier for the body to absorb anyway even if a person doesn’t have a mutation.

      1. Debora Barnes-Josiah Avatar
        Debora Barnes-Josiah

        No argument there. Perhaps rephrasing your blog to something like “natural forms of folate or methylfolate are most beneficial,” which does not suggest to the casual reader that she just ditch any multivitamin.

        1. Roxana Avatar

          If I may chime-in. . .

          Debora, I venture to say that the vast majority of people reading Wellness Mama and/or investigating how to handle their MTHFR mutation are not doing so “casually.” The same women who you see giving birth to children who sadly have a neural-tube defect are very likely not reading Katie’s site. The former are most likely more informed about their own health than their doctor (as was and is the case for me), and the latter probably have no idea that they could be suffering from the effects of the mutation. Anyone reading what Katie has written is not doing so “casually,” as you suggest. You are an epidemiologist, so I’m assuming that this point would be obvious to you.

          Additionally, before challenging her statement to “[ditch] your multivitamin,” it’d be very reasonable to consider the context in which Katie says so (as an aside, you must know that the vast majority of multivitamins are complete garbage; much more could be said about this); this is a blog/site that talks about nutrient dense food among other things. The information and advice she might be sharing should be considered contextually.

          1. Debora Barnes-Josiah Avatar
            Debora Barnes-Josiah

            Thank you Roxanna. First, let me say that I came across this blog while just looking for basic information about MTHFR. I don’t know if that makes me a “casual” reader or not. Second, for some reason, when I initially looked for previous comments it didn’t appear that there were any. So the ones I now see are clearly, as you say, not from “casual readers.” Not all readers post comments though, and some may just be curious about MTHFR for whatever reason.
            I still stand by my initial position, that the service you do by promoting good nutritional advice is weakened if it can be interpreted harmfully. The statement “Studies have been done that showed folic acid supplements increased cancer risk… one more reason to ditch processed foods and your multivitamin!” appears near the top of the blog, whereas the MTHFR Tips, which explains the folic acid vs. folate issue, are several paragraphs further down (yes, there is a reference and link further up about that, but no details). I don’t need to drag this out any further, I just ask that you remember the power in how things are worded. I’m sure we all have the same goal – healthy women, healthy pregnancies.

  15. Kristi Kearl Avatar
    Kristi Kearl

    Oh. My. WOW. I am nearly speechless. Thank you for explaining this! I have not been tested for a MTHFR genetic defect, but your words are ringing LOUDLY in my ears, and my guess is that this absolutely has been a problem for me and would explain why I’ve been feeling so terrible for the past 2 years. I am going to follow through on the testing protocol and in the meantime take steps to help myself as though I have the defect. Thank you, thank you, thank you!!

  16. Shannon Chambers Avatar
    Shannon Chambers

    Thank you so much for the breakdown of information. After years of complaining to my primary care doctor about fatigue, weight gain, and brain fog (who only tested TSH), I finally went to a private practice doctor who specializes in hormones. I, too, was diagnosed with Hashimotos and MTHFR mutation. I was given information about folic acid and supplements to avoid and encouraged to go gluten-free. Thank you for sharing your research.

  17. Lisa Avatar

    Julia, there are different websites that you can upload your raw data to and it will read the results for you. There are some links in this article. 🙂

    1. Julia Avatar

      Thank you Lisa! Encouragement received to read this thread thoroughly, I appreciate you taking the time to respond 🙂

  18. Julia Avatar

    Hi, I did the 23 and me testing to find out if I have the MTHFR mutation, but even after getting the data back, I don’t know if I have it or not! There’s no easy way to tell from the results, and when I called them, they were totally evasive and did not help me see how on earth to tell from the report whether I have MTHFR or not. Am I missing something? It is that you have to take the results to someone who is trained to interpret them?

    1. Alyssa D Avatar

      Hi Julia, you can find out by downloading your “Raw Data” zip file on 23andMe. Then upload it online to a site called Genetic Genie.org. They are a free site that will let you know of any genetic polymorphisms in the MTHF, as well as other health relevant SNPs that may be found in your raw data. This is the site most people find out about their mutations on. As far as getting the results interpreted, I recommend the HHP that interpreted mine. I sent her my raw data zip file from my 23andMe, and she sent me a nice report containing all of my mutations, what they mean, what symptoms are associated with them, and personalized a recommended protocol for me. Certain combinations of MTHF with other mutations like DAO, COMT, CBS, VDR, & others need to be considered before simply treating with methylfolate. Otherwise, if the other SNP’s aren’t taken into account, methylfolate can exacerbate symptoms for some with certain SNP combinations. I found this to be super confusing, so I paid to get it all done for me at http://www.elevatedhealthsolutions.com. They were having a September Sale for this service so it was well worth the money in my opinion, because the report contained lots of information, and helped me to understand exactly what these mutations meant, what to take, what to avoid, including foods and things.

      1. Julia Avatar

        Hi Alyssa,

        I am super grateful to you for taking the time to respond to me, you’ve really helped me so much, thank you a million! Now I know what to do for the next step…solving the riddle of why I don’t sleep at all at night for days on end. Bless you and thanks again!


  19. Stacey Avatar

    Are any of these tests, or Dr. Visits covered by insurance, if so, any in the Los Angeles area, that can be recommended? thank you!

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