HINT: Folic acid reduces the risk for spina bifida, and anencephaly, which are the two most common neural tube defects (NTDs). When folic acid is in a vitamin supplement, and is taken one month before conception and throughout the first three months of pregnancy (trimester), it has been proven to reduce the risk that a pregnancy will be affected by a neural tube defect up to 70%. Folic acid is required for the production of DNA, which is necessary for the rapid cell growth needed to make fetal tissues and organs early in pregnancy. That is why it is important for a woman to have enough folic acid in her body both before and during pregnancy.