A: Folic acid is a B vitamin essential for cell division and growth throughout our lifetime. This nutrient is necessary in DNA synthesis, function and repair, and is especially important for rapidly growing cells. You should continue taking folic acid throughout your pregnancy to support your baby's development. Women with folic acid deficiencies may have a higher likelihood of delivering prematurely or of having babies with low birth weight. Women carrying twins are advised to double their intake of folic acid.

Taking adequate daily folic acid before conception and during the first trimester will lower your risk of having a baby with a neural tube defect. The most common neural tube defects are spina bifida (a spinal abnormality which can cause paralysis) and anencephaly (a fatal malformation of the brain and skull). Additionally, early folic acid may reduce the chances a baby would develop a heart defect, cleft palate or cleft lip.

Folic acid in foods is called folate. Good dietary sources include green leafy vegetables (such as spinach and turnip greens), dry beans and peas, and orange juice. Many foods including grain products, cereals and pastas are fortified with folic acid, which helps reduce the rates of neural tube defects.

Folate is needed to prevent anemia in adults as well as children, and may play a role in heart disease and cancer. Researchers are studying whether folic acid supplements may reduce the risk of cancer and heart disease in adults. Because of these reasons, I recommend that you continue taking your folic acid supplement during your pregnancy and lactation. In fact, woman of childbearing age should consume at least 400 mcg of folic acid a day.

Folic acid is a water-soluble vitamin, which allows your body to excrete what it doesn't need. The only risk of excessive folic acid is that it can mask symptoms of a vitamin B12 deficiency. This is more of a concern in the elderly, and should not affect your decision to take folic acid during pregnancy.