Take folic acid before you become pregnant.

What you need to know:
Folic acid, a B vitamin, helps prevent birth defects of the brain and spinal cord when taken before the end of early pregnancy. It is available in most multivitamins, as a folic acid-only supplement and in some foods.

What you can do:
Take a multivitamin with 400 micrograms of folic acid every day before pregnancy, as part of a healthy diet.

Eat a healthy diet that includes foods that contain folate, the natural form of the vitamin. Such foods include fortified breakfast cereals, dried beans, leafy green vegetables and orange juice.

Folic acid works, but it only works if taken before and during the first few weeks of pregnancy when the neural tube is developing into the brain and spinal cord. When the neural tube does not close properly, a baby is born with a very serious birth defect called a neural tube defect (NTD). About 3,000 pregnancies are affected by NTDs each year in the United States. If all women took adequate folic acid before conception and during pregnancy, 50 to 70 percent of NTDs could be prevented.