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. Sherry Howard Avatar
    Sherry Howard

    Please tell me what type if medical professional can determine if me and my son have thi

  2. Memphis Avatar

    I am 18 years old. I found out when I was 16 that I have the C677T mutation. As I haven’t gotten my paperwork to confirm, I believe I was told I was homozygous for this and on top of that, I have another mutation; I just have got confirmation of the name. My family and friends think I’m being dramatic and it’s “not a death sentence” but it’s some pretty serious stuff. I’m still trying to get as much info as possible. My father is heterozygous for a mutation (A1298C I believe) and he had a massive heart attack at 38 (he made it but still scary).

  3. Brielle Avatar

    Can you recommend a multivitamin you like or take considering MTHFR gene mutation. I have a double mutation and looking for a good option.

  4. Erin Avatar

    Wow thank you so very much for putting such a comprehensive information report together! 🙂 I’ve been researching for a number of days now about the MTHFR gene variation because my husband recently found out he has that. This has helped me so much to get some good answers. Thank you so much!! 🙂

  5. Kristi Avatar

    Hi, my name is Kristi Tornabene, and I am writing a health coaching book. I am also MTHFR, and I would like to use the information on this page, to help my friends.

  6. Annmarie Avatar

    Hello my son has adhd and I’m researching the mutation which i believe he may have. I’m looking for the best (brand) multi vitamin to give him. He currently takes smarty pants daily. Can someone tell me what ones you take. Thank you.

  7. Cindy Avatar

    Hi Katie, thank you so much for the information. My husband and I are currently TTC and I will am expecting to test my HCG tomorrow.

    However, I just learned that I have one copy C667T, heterozygous and have been taking a very good and powerful prenatal SimplyOne by Super Nutrition that contains 1,000 MCG! 😐 If I am pregnant, will that hurt or cause any damage to my baby? I’m very nervous about this as I took it all of 2018.

    I plan to switch tomorrow to Naturelo Prenatal Whole Food Multivitamin as it contains Folate and MethylB12 and just increase my Vitamin D3 by another 3,000 IU (it only contains 800 IU) too low for me per NP Dr. I would really appreciate your thoughts or suggestions, thank you.

    By the way, I’m 45 years young TTC Baby #1

  8. Angel Evenson Avatar
    Angel Evenson

    I love this article. We, my family of 4, are currently being tested for the MTHFR mutation. We also follow all of the tips you give, if nothing else it makes you feel amazing! I am a research fanatic, so thank you for all you do!

  9. Atarah Avatar

    Since the mineral magnesium is essential in some 600 enzymatic processes and MTHFR is an issue of an enzyme I would suggest you investigate the use of various forms of magnesium supplements (not oxide) as a possible solution. Perhaps MTHFR is a symptom of a mineral deficiency and not a root cause issue.

  10. Darla Armstrong Avatar
    Darla Armstrong

    It was recently announced that 23andMe is changing their API in about a week, which means that sites like genetic genie, etc. are likely to be affected, and may no longer work. I recommend that all of you download your raw data, run it through at genetic genie, and save your mutation report as soon as possible.

  11. Erica Avatar

    Thank you so much for your article on this topic! I’ve had 2 “unexplained” miscarriages and have been trying to find out what is happening with my body to cause them. I learned my father has 2 MTHFR mutations, I’m not sure if I do or not because I’ve seen 2 Dr’s now, who both say this “diagnosis” is a “joke” and would have absolutely nothing to do with why I’m not carrying. I’ve even tried talking about taking true folate VS Synthetic folic but they won’t listen and tell me to take folic not folate. I just don’t agree with that. Unfortunately I live in Kansas and have a lot of close minded Dr’s and haven’t been able to find one that knows anything on the mutation. I’ll def look at the Dr’s website you referred and try to find more information!

  12. Jovana Avatar

    Hi, I read your comment and wanted to tell you to avoid getting detoxification done too often. You may have harder time eliminating toxins out of your body’s body which can lead to too much ammonia build up during detoxification. Sweating, drinking plenty of water, eating only organic food can be far more helpful in eliminating toxins with this gene than let’s saybdoing epsom salt baths

  13. Adrienne Avatar

    SUPER post!! So we’ll researched and filled with resources! Obviously you worked long and hard on this, and I thank you!!!!!

  14. Gretchen Avatar

    I did Ancestry.com. Is this a good test to see if I have MTHFR?

  15. Laney Avatar

    Thank you, so is a higher number on the test results for C677t and A1298c good, and a low number bad? Mine was C/C ~49.3% and A/A ~58.63%

  16. Tami Avatar

    So i just found out my son and I have this from our kenisiologist. My son has asthma and has been really sick the last few months. She tested him for this and me as well and both were positive. UGH I have the fibro symptoms with IBS and chronic fatigue. I have been gluten free for years which helps. now its a diet of no folic acid for him, for life.

  17. Kate Avatar

    Hi there – after having two miscarriages, I did genetic testing and found out I have a single MTHFR mutation. I also did nutrition testing a few weeks ago and just got the results back that show I’m deficient in B9. I found out I was 4 weeks pregnant on the same day I discovered the B9 deficiency. I was already taking Seeking Health Optimal Prenatal for the past few months, but was still deficient in B9 and now I’m worried my baby may have a neural tube defect. My question is do you think the baby will be ok since I was taking the prenatal with 800 mg L-MTHF, or do you think I should be concerned as I was still deficient? I started taking an extra 1,000 mg of methyfolate on the day I found out about the pregnancy, but I read that’s probably too late. Thanks for an advice!

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