Supplementation with Folic Acid or 5-Methyltetrahydrofolate and Prevention of Neural Tube Defects: An Evidence-Based Narrative Review.

Folic acid (FA), which in its chemical form is pteroylglutamic acid, is the fully oxidised, water-soluble, monoglutamic form of vitamin B9. This compound is part of the folate group but with higher bioavailability, and it is found in vitamin supplements and fortified foods and drugs. Folate metabolism is complex and associated with various metabolic pathways, all of which confer protection on the cell and allow its survival.