What Is Methylfolate and How Does It Work?

You’ve probably seen methylfolate (also called L-methylfolate or 5-MTHF) on supplement labels. Here’s what it is, in plain English.

Key takeaways

Folate is vitamin B9. Adults need 400 mcg DFE a day.
Methylfolate (5-MTHF) is the main form of folate in your blood.
Folic acid is the man-made form. Your body converts it before use.
If you could become pregnant, experts advise 400 mcg of folic acid daily.

Folate is vitamin B9

Your body needs folate to make DNA and to help cells divide. It also helps form red blood cells. Your body doesn’t store much, so you need a regular supply.

Good sources include leafy greens, beans and peas, citrus fruit and enriched grains. The NIH recommends 400 mcg DFE (dietary folate equivalents) a day for adults.

Folate, folic acid and methylfolate

Folate is the natural form found in food.
Folic acid is the man-made form added to enriched grains and most supplements.
Methylfolate (5-MTHF) is the active form your body uses.

How your body makes methylfolate

Folic acid and food folate go through several steps before they become methylfolate. The last step depends on an enzyme called MTHFR.

MedlinePlus describes the result as “the primary form of folate found in blood.” A methylfolate supplement provides this form directly.

What methylfolate does

Methylfolate helps turn an amino acid called homocysteine into methionine, which your body uses to build proteins. This step also needs vitamin B12, which is why the two are so often paired.

What about MTHFR?

MTHFR gene variants are common. The CDC says more people in the US carry at least one copy of the C677T variant than don’t.

The NIH notes that methylfolate might suit some people with this variant better, because their bodies can use this form more easily. The CDC adds that people with MTHFR variants can still process folic acid. If you have a test result, ask your doctor what it means for you.

Who should pay attention to folate?

Anyone who could become pregnant. The CDC and NIH advise 400 mcg of folic acid a day, even with an MTHFR variant.
People with a limited diet that is low in vegetables, beans and enriched grains.
People who drink heavily.
People with absorption problems such as celiac disease, or who take methotrexate, sulfasalazine or some anti-seizure medicines.

When to talk to your doctor

Ongoing tiredness, weakness, shortness of breath or a sore tongue can have many causes, including low folate or B12. A simple blood test can check your levels.

Frequently asked questions

Is methylfolate the same as folic acid?

Both are forms of vitamin B9. Methylfolate is already active, while folic acid is converted first.

Can I get enough folate from food?

Most people in the US do, according to the NIH. A supplement can help fill gaps in a limited diet.

Is methylfolate OK during pregnancy?

The CDC and NIH recommend 400 mcg of folic acid a day for anyone who could become pregnant. Talk to your doctor before using any other form.