Folic Acid Side Effects — Can You Get Too Much?

6. MTHFR Mutations

The MTHFR gene regulates an enzyme involved in folate metabolism. Some people have mutated variants of the MTHFR gene known as single nucleotide polymorphisms or SNPs. SNP mutations make the conversion of folic acid into folate less effective. A pregnant woman with a MTHFR mutation may take folic acid supplements — as is usually recommended — and develop elevated levels of folic acid in the bloodstream. This circulatory folic acid interferes with homocysteine breakdown. High levels of homocysteine increase the risk of blood clots and potential miscarriage in the first trimester.