Don’t Miss Out On Methylated B Vitamins

Why They’re Especially Important for Women with MTHFR Variants

Folate (vitamin B9) is one of the most talked-about nutrients in prenatal health. If you're planning to get pregnant, or already are, you’ve probably heard about its critical role in overall fetal development, as well as its particular importance in preventing neural tube defects.

But here’s what many women don’t realize: just taking folate isn’t always enough. If your body can’t use it properly, which can happen with certain genetic variants, it may not actually be supporting your pregnancy the way you think it is.

What Are Methylated B Vitamins?

Methylated B vitamins are simply the active forms your body can use immediately, no conversion required. For example, 5-MTHF is the active form of folate, and methylcobalamin is one of the most absorbable forms of vitamin B12.

Here’s the catch: a lot of conventional supplements still use synthetic or less active forms of these vitamins, like folic acid or cyanocobalamin. Your body has to convert these into their usable forms first, and if you have a common MTHFR gene variant, that process might not be very efficient. So even if it looks like you're getting enough, your body may not actually be able to use those nutrients the way it should.

What Is the MTHFR Gene?

MTHFR stands for methylenetetrahydrofolate reductase which is an enzyme needed to activate folate in our body. The MTHFR gene tells your body how to produce this enzyme, which plays a central role in methylation, a process that influences everything from DNA repair and detoxification to hormone balance and mood regulation.

Some women inherit variants of this gene that reduce how well this enzyme functions, which can impact your ability to convert folic acid into a usable form by as much as 30%- 70%! This can have a significant impact, especially during preconception and pregnancy when nutrient demands are high.

Why Methylated B Vitamins Matter

Folic acid is still the form of folate present in many prenatal supplements due to its cost and shelf life. However, folic acid may not be very helpful for those with MTHFR variations. 

In the early stages of pregnancy, when fetal development is rapid, methylated B vitamins are especially necessary for certain functions. They play a role in hormone regulation, DNA synthesis and repair, detoxification, and egg quality. These vitamins also help improve a mother's mood and mental health since methylation influences the synthesis of neurotransmitters. For this reason, many practitioners now advise moving to methylated versions of folic acid, such as 5-MTHF and methylcobalamin, as they are more bioavailable. Using these active forms can lower the likelihood of deficits that could impact fetal development or fertility in women with MTHFR mutations.

Methylation’s Role in Fertility and Pregnancy

Methylation is like the mom who keeps everything in order behind the scenes. When it's functioning properly, you might not notice it, but when it's not, things can fall apart quickly.

From a pre-conception standpoint, methylation promotes ovulation, balances hormone levels, and supports healthy egg development during preconception and pregnancy. During pregnancy, it helps keep the placenta healthy and is necessary for the development of your baby’s neural tube and brain. Adequate methylation support may also lower the incidence of miscarriage and birth abnormalities. Overall, healthy methylation creates the foundation for a more stable pregnancy.

How to Choose the Right Prenatal

If you’re trying to conceive, currently pregnant, or simply want to support methylation, choosing the right supplement matters. On the label, look for folate listed as “5-methyltetrahydrofolate” or “L-5-MTHF” instead of folic acid. Also, choose forms of B12 that don't need to be converted, such as methylcobalamin or adenosylcobalamin. Other nutrients that promote methylation- such as vitamin B6, riboflavin (B2), and choline- are also beneficial.

Food-Based Support

Food has a significant impact as well, even though supplements help close the gaps. Whole foods have the advantage of having many nutrients in their active forms, which your body can use immediately. 

For natural folate, load up on leafy greens, lentils, avocados, and asparagus. You’ll find vitamin B12 in eggs, dairy, grass-fed meats, and shellfish. Choline, a crucial methylation nutrient, is rich in egg yolks, liver, and soybeans. You can also support the methylation cycle with foods like beets, mushrooms, sunflower seeds, and quinoa. Even if you carry an MTHFR variant, your body can make excellent use of these nutrient-dense whole foods, making a real-food foundation just as important as smart supplementation.

What’s in Your Prenatal?

Whether you know you carry an MTHFR variant or you’re just trying to be proactive, choosing methylated B vitamins is a simple and effective way to support fertility, pregnancy, and long-term well-being. When your body has access to nutrients in their active forms, it can support healthy methylation, which has ripple effects across your hormone and energy levels, as well as your baby’s development. Making a simple switch to the right form of B vitamins can go a long way in supporting both your well-being, and your baby’s healthy start!

Written by: Jen Dela Cruz, MS, RD, CDCES