Folic acid: Pregnant women need 400 micrograms (400 mcg) of folic acid every day to help prevent birth defects.
Folic acid is important for any woman who could possibly become pregnant. Folic acid is a B vitamin that helps prevent serious birth defects of a baby's brain or spine called neural tube defects. Getting enough folic acid can also help prevent birth defects like cleft lip and congenital heart disease.
Getting enough folic acid is most important very early in pregnancy, usually before a woman knows she is pregnant. So, at least one month before you try to become pregnant you should make sure you're getting enough folic acid. Women who are already pregnant need to get enough folic acid every single day.
An easy way to get enough folic acid is to take a multivitamin every day. Most multivitamins sold in the U.S. contain enough folic acid for the day. But be sure to check the label! Choose a multivitamin that contains 400 mcg or 100% of the Daily Value (DV) for folic acid.
Another way to get enough folic acid is to eat a serving of breakfast cereal that contains 100% DV for folic acid, every day. Check the nutrition label on the box of cereal to be sure. It should say "100%" next to folic acid. Orange juice, spinach and legumes are also good sources of folic acid.
Source: National Women’s Health Information Center, U.S. Department of Health and Human Services, www.womenshealth.gov