Can I take folic acid with MTHFR?

CDC says yes. People with common MTHFR variants can process folic acid, and CDC recommends 400 mcg a day for anyone who could become pregnant, variant or not.

Is methylfolate better than folic acid for MTHFR?

ODS says some people with the C677T variant might benefit from 5-MTHF, but the evidence is inconclusive, and only folic acid has been shown to prevent neural tube defects.

How much lower is folate with MTHFR C677T?

CDC says people with two copies (677 TT) have about 16% lower blood folate than the CC genotype on the same folic acid intake.

Does MTHFR A1298C matter?

CDC says there is not enough evidence that the A1298C variant alone meaningfully affects how the body processes folate.

MTHFR and Folic Acid: What CDC and NIH Say

Short answer: No, according to CDC. It says people with the common MTHFR variants can process all types of folate, including folic acid, and that these variants are not a reason to avoid it. People with two copies of the C677T variant have about 16% lower blood folate on the same intake, but 400 mcg a day still raises folate levels. Folic acid is the only form of folate shown to prevent neural tube defects.

What MTHFR is

MTHFR is a gene for an enzyme that helps the body turn folate into its active form, 5-methyltetrahydrofolate (5-MTHF). Everyone has two copies of the gene. The most common variant is C677T; another is A1298C. CDC says more people in the US have one or two copies of C677T than do not, and that it is more common in Hispanic people.

The NIH Office of Dietary Supplements (ODS) says people with two copies of C677T have a reduced ability to make 5-MTHF, which can raise homocysteine and the risk of neural tube defects (NTDs). ODS gives these rates of two-copy C677T: about 25% of Hispanic people, 10% of white and Asian people and 1% of Black Americans.

What CDC says about folic acid

People with an MTHFR variant can process all types of folate, including folic acid.
On the same folic acid intake, people with the 677 TT genotype have only slightly lower blood folate, about 16% lower than the CC genotype.
Folic acid intake matters more than genotype for blood folate, and 400 mcg a day raises folate whatever the genotype.
There is not enough evidence that A1298C alone has a meaningful effect.
Taking folic acid at the recommended amount has not been shown to cause harm, and more than recommended is not necessarily better for preventing NTDs.

CDC calls the idea that people with a variant should avoid folic acid and use 5-MTHF instead "not true", and says folic acid is the only type of folate shown to help prevent NTDs. ODS agrees that CDC recommends 400 mcg a day of folic acid, not 5-MTHF, even with the C677T variant.

Where 5-MTHF fits

ODS says the evidence on extra benefit for people with the variant is inconclusive and that some might benefit from 5-MTHF. It also notes the body absorbs 5-MTHF in supplements as well as or better than folic acid. What has not been shown is that 5-MTHF prevents NTDs, because the trials that proved prevention used folic acid. CDC also points out that rare MTHFR variants, unlike the common ones, can have real health effects and are worth raising with a doctor or genetic counselor.

Planning a pregnancy

The CDC advice is the same with or without a variant: 400 mcg of folic acid a day, starting at least a month before conception (see when to start folic acid). A doctor may suggest more for other health conditions. Dose Track can keep the prenatal vitamin on a daily reminder, next to any fertility medicines.

Read more on Dose Track: Folate · Female fertility · PCOS · Dietary supplement

General education drawn from labels, public health agencies and published studies, not personal medical advice. Your prescriber, pharmacist and the label that came with your medicine are the final word. Questions for other users? Ask in the Dose Track community.

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