If you're pregnant or might become pregnant, it's critically important to get enough folic acid, the synthetic form of vitamin B9, also known as folate.
Folic acid helps prevent neural tube defects (NTDs) – serious birth defects of the spinal cord (such as spina bifida) and the brain (such as anencephaly). The neural tube is the part of the embryo from which your baby's spine and brain develop. NTDs affect about 3,000 pregnancies a year in the United States