Women are advised to take prenatal vitamins before and during pregnancy. Prenatal vitamins are specially formulated multivitamins that supplement a diet and often make up for any nutritional deficiencies in the mother's diet.
The most important ingredient in prenatal vitamins is folid acid, a B vitamin. Folic acid can reduce your risk of having a baby with a serious birth defect of the brain and spinal cord, called the "neural tube."
In order to be effective, folic acid must be taken at least 1-2 months prior to conception. Because about half of all pregnancies are unplanned, the U.S. Public Health Service recommends that all women of childbearing age get 400-600 micrograms of folic acid each day. In fact, the FDA now requires that all flour products -- such as breads, buns, and bagels -- be fortified with extra folic acid. A woman who has had a prior child with a neural tube defect should discuss the appropriate dose of folic acid with her doctor before her next pregnancy. Studies have shown that taking a larger dose (up to 4,000 micrograms) at least one month before and during the first trimester may be beneficial.
While a daily vitamin supplement is no substitute for a healthy diet, most women need supplements to make sure they get adequate levels of these minerals. Not all prenatal vitamins are the same. You should take a prenatal vitamin that has about 100% of the recommended daily allowance (RDA).