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What Exactly Is Methylation & Why Is It So Essential To Overall Health?

Stephanie Eckelkamp
Author: Expert reviewer:
Updated on July 6, 2023
Stephanie Eckelkamp
Contributing Health & Nutrition Editor
By Stephanie Eckelkamp
Contributing Health & Nutrition Editor
Stephanie Eckelkamp is a writer and editor who has been working for leading health publications for the past 10 years. She received her B.S. in journalism from Syracuse University with a minor in nutrition.
Ashley Jordan Ferira, Ph.D., RDN
Expert review by
Ashley Jordan Ferira, Ph.D., RDN
mbg Vice President of Scientific Affairs
Ashley Jordan Ferira, Ph.D., RDN is Vice President of Scientific Affairs at mindbodygreen. She received her bachelor's degree in Biological Basis of Behavior from the University of Pennsylvania and Ph.D. in Foods and Nutrition from the University of Georgia.
This article was produced to support the mindbodygreen supplements+ line. Our supplements adhere to the highest standards of ingredients and quality. We hope you enjoy these products. For more information, click here.

If you're interested in supporting health on a foundational or cellular level, you can't overlook methylation. Methylation is a simple yet vitally important biochemical process in the body that is widespread and helps regulate the activity of our cardiovascular, neurological, reproductive, and detox systems. (To name a few.)

Methylation takes place approximately one billion times per second and affects nearly every essential process in the body, according to functional medicine physician Robert Rountree, M.D. But when this vital process is not optimized—which can happen as a result of a variety of dietary, lifestyle, and genetic factors—your physical and mental well-being, from a cellular to whole-body level, will be suboptimal or worse.

Here, we break down what methylation is, what can interfere with it, and how to support methylation to enhance overall health.  

What is methylation?

At the most basic level, methylation and demethylation refer to the transfer of methyl groups—simple structures of one carbon and three hydrogen molecules (CH3)—to and from various bioactive compounds in the body. These compounds (e.g., proteins, enzymes, hormones, and more) must be methylated in order to function optimally or to create other substances required by the body.

For example, methylation is essential for the production of certain bioactive vitamins (e.g., folate and vitamin B12), amino acids, neurotransmitters, hormones, red blood cells, DNA, RNA, and antioxidants that directly impact cardiovascular, neurological, reproductive health, energy production, detoxification pathways, and more.

The process of DNA methylation1, a unique subset of methylation physiology, is somewhat different and specifically refers to the attachment of methyl groups to certain segments of DNA, which, in turn, tells the body what genes should be turned on and off. DNA is the code or instructions for a wide array of functional proteins to be made throughout our body—from signaling molecules and neurotransmitters to hormones, antibodies, and more.

Typically, DNA methylation turns genes off, while demethylation turns genes on. DNA methylation is an example of epigenetics2—that is, changes in the physical structure of DNA caused by your behaviors (including nutrition, lifestyle, etc.) or environment, which can be passed down from parent to child. The pivotal and fascinating process of DNA methylation is relevant to life and health—from early development to immunity, memory formation, and more.

The methyl groups that participate in methylation come from a variety of micronutrients in your diet collectively dubbed "methyl donors3," which include folate (B9), vitamin B12, vitamin B6, riboflavin (B2), betaine, choline, and several others.* You'll notice the prominence of essential B vitamins in this lineup. Folate is probably the most well-known methyl donor in the B vitamin family, so we'll use it as an example to highlight exactly how methylation works.

Let's walk through a methyl donor example

Once you consume folate from food or folic acid (found in fortified foods and certain supplements), the enzyme methylenetetrahydrofolate reductase (MTHFR) theoretically (the MTHFR gene codes for the MTHFR enzyme, more on that later) converts vitamin B9 into its bioactive form called methylfolate or 5-methyltetrahydrofolate (5-MTHF), which is fully activated and can now serve as a methyl donor for those widespread health functions mentioned earlier (think heart, brain, detox, energy, immunity, etc.).*

Specifically, this bioactive folate (5-MTHF) donates a methyl group4 to the amino acid homocysteine to convert it to the amino acid methionine. Not only does this directly support healthy homocysteine levels (i.e., helps them from getting too high) in the body, but also methionine can then be utilized to form S-adenosylmethionine (SAM-e).

SAM-e is incredibly important because it functions as a "universal methyl donor3" for all biological methylation processes in the body, including DNA methylation, which means it donates methyl groups to all sorts of acceptor molecules to support optimal physiological functioning globally in the body.  

After SAM-e has donated its methyl groups, it's converted back to homocysteine, which can go on to produce cysteine (another amino acid) and then master antioxidant glutathione, or to accept another methyl group from 5-MTHF and repeat the cycle. Taken together, the activation of folate (aka, the “folate cycle”) and the homocysteine conversion onto methionine and ultimately SAM-e (dubbed the “methionine cycle”) enable and fuel methylation. The methylation cycle, that is.


Methylation is a biochemical process that involves the addition of a methyl group (-CH3) to a molecule. In the context of genetics and molecular biology, methylation commonly refers to the addition of a methyl group to DNA or RNA molecules. Methylation can affect gene expression and play a role in various biological processes.

What is the role of methylation?

A biochemical and epigenetic process with truly systemic reach and implications, methylation plays several big roles in the body. One of those big roles briefly mentioned above is the recycling of the amino acid homocysteine to keep its levels in a healthy, optimal range. As nutrition scientist Ashley Jordan Ferira, Ph.D., RDN explains, "Your health care practitioner can measure homocysteine levels with a simple blood test."

Ferira goes on to say, "Achieving and maintaining healthy homocysteine levels is required for the optimal production of numerous amino acids, neurotransmitters, hormones, and antioxidants, which participate in processes throughout the body and mind."* Indeed, this biomarker has massive implications for our overall health, but especially for cardioprotective blood vessel functioning and neuroprotective actions for thriving brain function.

Some important compounds (i.e., hormones, neurotransmitters, coenzymes, and other bioactives) that require methylation to be manufactured include the following:

Methylation also supports natural detoxification pathways in the body by assisting in the appropriate breakdown and removal5 of various hormones and toxins by transforming them into a form that is easier to excrete.

Furthermore, methylation helps produce the powerful antioxidant glutathione, which binds to and helps safely remove toxins such as heavy metals from the body, according to functional medicine doctor Mark Hyman, M.D.

Finally, as mentioned above, DNA methylation can help silence genes that might otherwise up your risk for unruly processes in the body that can lead to suboptimal organ functions and worse. 


The primary role of methylation is to recycle the amino acid homocysteine to keep its levels in a healthy, optimal range. 

Causes of suboptimal methylation

One potential cause of poor methylation is having the MTHFR gene variant6, which reduces the efficiency of transforming dietary folate and folic acid to their active methylfolate (5-MTHF) form. This can lead to a functional folate deficiency and a lack of methyl groups required for methylation (for all the essential biological actions described above).

While individual responses vary, this suboptimal methylation can manifest on a spectrum in terms of its health impact. And as Ferira points out, "Interestingly, the MTHFR genetic variant is not rare but rather widespread, with some estimates indicating that approximately 40% or more of the population could be impacted. That's over a hundred million Americans alone."

Certain diet and lifestyle habits can also interfere with optimal methylation. In addition to inadequate consumption of folate-rich nutrition and failing to take in bioactive forms of B vitamins and other methyl-donor nutrients, "too much alcohol or coffee consumption, smoking cigarettes, and high exposures to arsenic in food and water can all deplete the body of methyl groups needed for optimal methylation—unless you're taking steps to replace them with food or supplements,"* says Rountree.

Consequences of suboptimal methylation

So what happens when methylation isn't top-notch? "Methylation affects all physiological processes, so we see a wide range of problems when it's compromised," says functional medicine physician Karyn Shanks, M.D. These potential issues can truly span the entire body and include:

  • Suboptimal energy levels & mood: Interference with neurotransmitters may contribute to low mood, feelings of anxiousness, and difficulty sleeping, according to Ali Miller, R.D., L.D., CDE, registered dietitian.
  • Subpar detoxification abilities: Inability to adequately excrete toxins can drive inflammatory processes and negatively affect skin and energy, as well as gut, musculoskeletal, and reproductive health, Miller also notes.
  • Elevated homocysteine levels: Ferira adds that elevated homocysteine levels resulting from poor methylation "is not only a lab test result you'll want to avoid, but more importantly, over time, this imbalance can contribute to vascular issues that are directly pertinent to your heart and brain." She underscores this further, explaining that, "normal methylation and healthy homocysteine levels are inextricable and pivotal to optimize for cardioprotective and neuroprotective benefits throughout life."

How to learn about your own methylation cycle

Methylation influences nearly every aspect of your health, so it can be difficult to assess methylation function based on how you're feeling alone. Echoing Ferira's insights on the importance of healthy homocysteine levels, Rountree recommends a simple homocysteine blood test.

Because methylation is essential for homocysteine processing and recycling, elevated homocysteine levels could be a clinical biomarker indicator of suboptimal methylation. Ferira shares that, "depending on the practitioner, they may consider age- and gender-specific homocysteine ranges to test for normalcy." For example, for ages 18 to 60, a homocysteine result of less than 14.5 µmol/L is considered in the normal range. But in functional and integrative medicine, a more conservative homocysteine level (less than 7 μmol/L7) may be considered optimal.

In cases of elevated homocysteine, supplementing and eating more foods that are rich in methyl-donors in their bioactive formats can support methylation and bring homocysteine levels back to a healthier range.* 

Although quite common in integrative, functional, and precision medicine settings, genetic testing to determine if you have the MTHFR variant isn't necessary to assess your methylation status. It's definitely informative but typically not even recommended unless you have elevated homocysteine and specifically want to know if your genes are part of the equation.

If you're interested in genetic testing, consider working with an integrative or functional medicine practitioner who can run a comprehensive panel and make targeted, personalized recommendations for lifestyle changes and nutrition protocols based on those results. 


A simple homocysteine blood test can help you understand your own methylation status. High homocysteine levels indicate suboptimal methylation, and you may want to consider working with integrative medicine practitioner to help bring your levels to a healthy range.

How to support methylation

There are plenty of ways to support methylation—and nutrition plays the biggest role. Methylation relies heavily on fully activated folate, along with other methyl donor nutrients5 such as vitamin B12, vitamin B6, choline, and betaine, says Miller.

In addition to those key players, Ferira adds an oft-forgotten B vitamin into the methylation mix: "Riboflavin, aka vitamin B2, is a required cofactor for the MTHFR enzyme, required for folate recycling8, so it can be the amazing methyl donor it's designed to be,"* she explains. Talk about B vitamin synergy.

Here's how you can get your fill of each methyl donor from food:

  • Folate (vitamin B9, but remember, it's not in its fully bioactive 5-MTHF form yet): Spinach, asparagus, mustard greens, kale, broccoli, avocado, asparagus, beets, citrus, animal proteins (particularly beef liver), legumes, nuts, and seeds 
  • Vitamin B12: Meats and meat products, poultry, fish, shellfish, and eggs
  • Vitamin B6: Meats, whole grains, pistachios, sesame seeds, sunflower seeds, garlic, legumes, and prunes 
  • Choline: Meat, fish, poultry, dairy, eggs, shiitake mushrooms, legumes, and cruciferous veggies
  • Betaine: Quinoa, beets, spinach, whole grains, sweet potato, meats, and poultry
  • Riboflavin (vitamin B2): Meats (especially organ meats), dairy, eggs, fortified cereals and grains, and green vegetables (e.g., asparagus, broccoli, and spinach)

Also, try not to consume anything to excess (good advice in general, not just for methylation health optimization!)—particularly alcohol or coffee, which can deplete your body of methyl donors and mess with methylation pathways, including DNA methylation

Smart supplements with methyl donors woven into the very fabric of their formulation (like mbg's methylation support+, which features a specific combination of bioactive B vitamins and betaine to optimize methylation function and status) can come in handy, too.*

For example, if you're seeking to support healthy homocysteine levels, or you know you have the MTHFR gene variant, taking a supplement that already contains the bioactive form of folate (methylfolate, aka 5-MTHF) plus the fully activated forms of other B vitamins can help you absorb and utilize these methylation-essential nutrients most efficiently.*

While there's still some debate on the best interventions and approach, Rountree has been using and recommending methylfolate in his clinical practice for the past 20 years. Ferira concurs, adding, "This precision approach of delivering bioactive methyl donors and other key methylation cofactors is shared by most practitioners in the integrative medicine and nutrition sectors."*

We hope more methylation health discussions will go mainstream, because, "the methylation cycle and DNA methylation are probably some of the most underdiscussed, yet wide-reaching and essential, physiological processes in the body. I'm ready for their prime time because so many people would benefit from methylation optimization," says Ferira. She goes onto say that, “The right combo of bioactive B vitamins and bioactives are a gene-focused and biohacking nutrition approach to maximize your methylation potential."*

Finally, try to prioritize high-quality sleep and stress management practices, says Shanks, as both stress and inadequate sleep9 have been shown to negatively affect DNA methylation. Boosting your daily physical activity levels can help with both, as well as promote detoxification and possibly even lower homocysteine levels10.  


Nutrition plays a big role in how smoothly methylation processes run. Eating foods rich in folate, vitamin B12, vitamin B6, and riboflavin and taking targeted supplements can support healthy methylation.

The takeaway

Methylation influences just about every essential process in the body. It's needed for the production of amino acids, neurotransmitters, hormones, red blood cells, DNA, RNA, and antioxidants; for proper detoxification of hormones and toxins; and for determining whether certain genes will be expressed or not (the power of epigenetics). It's a big deal.

But when this vital process is compromised (which can happen as a result of a variety of dietary, lifestyle, and genetic factors) your physical and mental well-being, from a cellular to whole-body level, will pay the price.

The good news: A simple homocysteine test can help you get a glimpse of your own methylation cycle health and help determine whether you need to make any dietary or lifestyle changes—such as supplementing with a precision nutrition solution like mbg's methylation support+—to promote healthy methylation every day.* 

If you are pregnant, breastfeeding, or taking medications, consult with your doctor before starting a supplement routine. It is always optimal to consult with a health care provider when considering what supplements are right for you.
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Stephanie Eckelkamp author page.
Stephanie Eckelkamp
Contributing Health & Nutrition Editor

Stephanie Eckelkamp is a writer and editor who has been working for leading health publications for the past 10 years. She received her B.S. in journalism from Syracuse University with a minor in nutrition. In addition to contributing to mindbodygreen, she has written for Women's Health, Prevention, and Health. She is also a certified holistic health coach through the Institute for Integrative Nutrition. She has a passion for natural, toxin-free living, particularly when it comes to managing issues like anxiety and chronic Lyme disease (read about how she personally overcame Lyme disease here).