Folic acid is a B vitamin that is responsible for helping maintain normal growth and development in the body. The Centers for Disease Control and Prevention says that folic acid is necessary for helping to produce new cells, and can be essential in the development of cells that are made each day, such as the skin, hair and nails. It also helps the body make red blood cells that carry oxygen from the lungs to all parts of the body, says March of Dimes.
Where folic acid shines the brightest is in the prevention of key birth defects of the brain and spine known as neural tube defects, or NTDs. NTDs develop during the first month of pregnancy when the embryo is under rapid development — a period when many women may not even know they are pregnant. Some studies also show that folic acid may help prevent heart defects in a baby and cleft lip and palate disorders.
Women of childbearing age are urged to take at least 400 mcg of folic acid each day, according to the CDC. Doing so ensures the body has enough residual folate available to promote proper baby development should a woman become pregnant. Many obstetricians recommend that if a woman is planning to become pregnant, she should begin taking folic acid a month or two before trying to conceive. Opt for multivitamins or prenatal vitamins that contain folic acid. 
March of Dimes says that women at high risk for NTDs should take 4,000 mcg of folic acid each day to help prevent an NTD. Begin three months before trying to get pregnant and continue through the first 12 weeks of pregnancy. Women who are at high risk include those with a previous pregnancy with an NTD. Prospective parents who had an NTD also are at an elevated risk.  
Folate also can be found in many fortified foods, such as breads, pastas, rices, and breakfast cereals, and can even be found naturally in other foods. These include peanuts, citrus fruits, asparagus, leafy green vegetables, and many beans. Foods also can be used to boost folic acid in the body.
WebMD says folic acid has also been linked to reduced risk of stroke, some types of cancers, Alzheimer’s disease, heart disease, and preeclampsia. So it is important to take it even if you are a man or a woman who is not planning to become pregnant.