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What is the MTHFR gene? A simple guide to understanding folate methylation
Written byLiz Connor
Reviewed byHeeral Tomlinson
Never heard of MTHFR? You're not alone. Here's what this much-talked-about gene actually means for your health – and whether methylated B vitamins are actually worth your time and money…
Summary
1What is MTHFR?
It’s a gene everyone has, which provides instructions for making an enzyme that helps the body convert vitamin B9 into an active form.
2What is methylation?
Methylation is the process of putting the conversion of vitamin B9 to work. It helps regulate things like gene activity and metabolism.
3Do I need to take methylated B vitamins?
If you're eating a varied diet and covering your nutritional bases, chances are your body is already handling the conversion process fine on its own.
You might have seen MTHFR popping up more in health conversations – but what is it and why does it matter? While diet and lifestyle play a big role in how we get and use nutrients, our genes can also have an influence. MTHFR is one of them, linked to how the body processes certain vitamins like folate.
Wondering what this hot-button term actually means and whether it’s something you need to be concerned about? We spoke to science communications manager, Heeral Tomlinson, to answer these questions.
What is MTHFR?
“MTHFR is a gene everyone has, which provides instructions for making an enzyme that helps the body convert folate into its active form (5-MTHF), otherwise known as vitamin B9,” explains Heeral.1
If that sounds complicated, think of it as a bit like a set of IKEA flat-pack instructions - the MTHFR gene is the manual and the enzyme is what actually gets assembled. When you eat foods rich in folate, like a big bowl of leafy greens for lunch, the vitamin isn’t immediately ready for your body to use. It has to be converted into an active form first.2
That’s where MTHFR comes in. The enzyme it produces helps turn folate into a usable form that your body then relies on for essential functions like making and repairing DNA.3
What is methylation and why is it important?
If MTHFR is the tool for converting folate, methylation is the process of putting it to work – together this is known as methylation.4 It’s basically a chemical process where your body adds small chemical tags (methyl groups) to molecules, helping regulate things like gene activity and nutrient metabolism.
Methylation is thought to have a hand in dozens of bodily processes, including the creation of certain hormones, proteins and red blood cells.5 It’s fundamental to cellular function and impacts everything from development6 to supporting the body's natural defenses.7
“It’s a normal chemical process that’s happening constantly in the body,” explains Heeral. Think billions of times a day, in virtually every cell.
So what does all of this have to do with B vitamins?
Quite a lot, as it turns out. A collection of B vitamins, like folate and B12, act like helpers that allow important processes in your body, like methylation, to happen properly.8 Most of the time, your body can manage this conversion without any trouble, but it's also why you might have recently started seeing methylated B vitamins being marketed on your feeds.
These specialist supplements contain nutrients that are already closer to that active, usable form, skipping a step in the process.
Do I need to take methylated B vitamins?
“For most people, this isn't something to worry about day to day," assures Heeral, who adds that if you're eating a varied diet and covering your nutritional bases, chances are your body is already handling the conversion process just fine on its own. "The key is making sure you're getting enough folate and other B vitamins overall, rather than assuming you need specialist supplements,” she stresses.
Standard non-methylated B vitamins, the kind you find in most shops and supermarkets, are perfectly fine for the vast majority of people, regardless of differences in B vitamin absorption genetics.
That being said, methylated forms do exist for a reason, and in certain specific situations (for example, if you have issues with converting standard B vitamins) a GP might suggest them. However, they’re not one to take blindly without consulting your doctor first.
Is it safe to take methylated B vitamins?
“Generally speaking, methylated B vitamins are considered safe for most people when they’re taken at appropriate doses,” says Heeral. They're widely available too, and for those who do choose to take them, they're often well tolerated.
“However, methylated forms tend to sit at the pricier end of the supplement shelf, and if you don't have a specific reason to choose them over standard forms, you may just be paying more for something your body doesn't particularly need. Also, high intakes of B vitamins, in any form, should be approached with care, and as with any supplement, sticking to recommended amounts is the sensible approach.”
Has MTHFR been overstated in wellness spaces?
Recently on social media, you may have scrolled past discussions about variations of the MTHFR gene, with some creators linking them to everything from fatigue and brain fog to anxiety and fertility issues - often in ways that go well beyond what the research actually supports.
“In many cases, these claims have been overstated,” says Heeral. “While the biology of MTHFR is real, online discussions often exaggerate its impact or suggest unnecessary testing or supplementation.”
It’s true that MTHFR variations are extremely common, with an estimated 60 to 70% of adults carrying at least one variant.9 For most people though, the actual real-world impact of that variation is very modest and Heeral assures it’s not something to lose sleep over. Most people with MTHFR variants have no symptoms, so testing isn’t routinely recommended in clinical practice.10
What are the simplest ways to support methylation?
Rather than reaching for a shelf full of specialist supplements, Heeral recommends focusing on the basics of good nutrition instead, which can have knock-on benefits for your energy, focus and overall wellbeing. Try…
- eating a varied, balanced diet – loading your plate with plenty of fibre, healthy fats, quality protein and carbohydrates
- including lots of folate-rich foods – like leafy greens, legumes, beans and lentils
- keeping an eye on your B12 – folate and B12 work so closely together that it's worth thinking about them as a pair
If you’re experiencing ongoing fatigue or have been told you have low B12 or folate levels, it’s worth speaking to your GP, who can rule out any underlying deficiencies or absorption issues.
MTHFR FAQs
MTHFR provides instructions for making an enzyme that helps your body convert folate (vitamin B9) into a form your cells can actually use.11 This then supports a range of essential functions, including DNA production and cell repair.
Methylation is a chemical process that happens constantly in virtually every cell in your body. It's essentially your body's way of activating nutrients so they can do their jobs properly.
Not necessarily, and it's worth being cautious of anything that suggests otherwise. Methylated forms are simply closer to the active form your body uses, requiring a little less conversion. But for most people, standard supplements work perfectly well. In certain clinical situations, specific forms may be recommended under medical supervision, however.
The final say
MTHFR and methylation might sound like something straight out of a GCSE biology exam, but for most people, they really aren't something to worry about. Focus on getting enough folate and B vitamins through your diet and your body will usually take care of the rest.
Thinking about taking a vitamin B supplement but not too sure what the options are and which one’s best for you? Check out our guide to the best blends of vitamin B, from oral sprays to liquid tinctures.
Disclaimer – This article provides informational advice and is not a substitute for medical care. Working with experts for accuracy, we take great care to ensure the information is up-to-date and relevant. However, you should always consult your GP or healthcare professional before using supplements or alternative products, particularly if you have medical conditions or are under supervision.
1. CDC. MTHFR Gene Variant and Folic Acid Facts [Internet]. Folic Acid. 2024. Available from: https://www.cdc.gov/folic-acid/data-research/mthfr/index.html
2. Crider KS, Yang TP, Berry RJ, Bailey LB. Folate and DNA Methylation: A Review of Molecular Mechanisms and the Evidence for Folate’s Role. Advances in Nutrition. 2012 Jan 1;3(1):21–38.
3. Leclerc D, Sibani S, Rozen R. Molecular Biology of Methylenetetrahydrofolate Reductase (MTHFR) and Overview of Mutations/Polymorphisms [Internet]. www.ncbi.nlm.nih.gov. Landes Bioscience; 2013. Available from: https://www.ncbi.nlm.nih.gov/books/NBK6561/
4. Menezo Y, Clement P, Clement A, Elder K. Methylation: An Ineluctable Biochemical and Physiological Process Essential to the Transmission of Life. International Journal of Molecular Sciences. 2020 Dec 7;21(23):9311.
5. Phillips T. The role of methylation in gene expression [Internet]. Nature.com. 2008. Available from: https://www.nature.com/scitable/topicpage/the-role-of-methylation-in-gene-expression-1070/
6. KOUKOURA O, SIFAKIS S, SPANDIDOS DA. DNA methylation in the human placenta and fetal growth (Review). Molecular Medicine Reports. 2012 Jan 24;5(4):883–9.
7. de la Calle-Fabregat C, Morante-Palacios O, Ballestar E. Understanding the Relevance of DNA Methylation Changes in Immune Differentiation and Disease. Genes [Internet]. 2020 Jan 18;11(1). Available from: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7017047/
8. Sobral AF, Cunha A, Silva V, Gil-Martins E, Silva R, Barbosa DJ. Unveiling the Therapeutic Potential of Folate-Dependent One-Carbon Metabolism in Cancer and Neurodegeneration. International Journal of Molecular Sciences [Internet]. 2024 Aug 28;25(17):9339–9. Available from: https://www.mdpi.com/1422-0067/25/17/9339
9. MTHFR genetic testing/counselling [Internet]. East Genomics. 2025. Available from: https://www.eastgenomics.nhs.uk/for-healthcare-professionals/clinical-genetics-services/east-anglian-medical-genetics-service/referrals/referrals-not-routinely-accepted/mthfr-genetic-testingcounselling/
10. Hickey SE, Curry CJ, Toriello HV. ACMG Practice Guideline: lack of evidence for MTHFR polymorphism testing. Genetics in Medicine [Internet]. 2013 Jan 3 [cited 2019 Jul 24];15(2):153–6. Available from: https://www.nature.com/articles/gim2012165
11. Hecker J, Layton R, Parker RW. Adverse Effects of Excessive Folic Acid Consumption and Its Implications for Individuals With the Methylenetetrahydrofolate Reductase C677T Genotype. Cureus. 2025 Feb 20;
