What is a prenatal supplement?
It's a multivitamin a pregnant woman (and a woman who's trying to conceive) takes to increase her nutritional intake of necessary vitamins and minerals. Neither the FDA nor the American College of Obstetricians and Gynecologists (ACOG) has set guidelines for what has to be in a multivitamin for it to be called a prenatal supplement, but your doctor or midwife will probably advise you to take one once you're planning to conceive or learn you are pregnant.

As a general rule, most prenatal supplements contain a greater amount of folic acid, iron, and calcium than you'll find in a standard multivitamin (such as Centrum or One-a-Day). Pregnant women need more of these nutrients than the average woman, especially folic acid, which reduces a baby's risk of neural tube birth defects such as spina bifida

You can buy prenatal supplements at the drugstore, or your doctor or midwife can write you a prescription. Depending on your needs (if you're expecting multiple babies, for example, or if you have given birth before to a baby with neural tube defects), you may be prescribed a supplement with even greater amounts of certain nutrients.

Do I need to take one? Why?

Not all experts agree. ACOG, for one, thinks a balanced diet will supply all the vitamins a woman needs to see her through her pregnancy. But most healthcare providers will recommend that you take a supplement, both from the time you decide to start trying to get pregnant through your pregnancy.

Why? It's almost impossible to meet your pregnant body's increased needs for nutrients through diet alone. Your body is making so much extra blood that you need about 30 to 60 mg of ironevery day (15 to 45 mg more than the RDA of 15 mg), and you need extra folic acid (up to 800 mcg) starting even before you get pregnant.

What vitamins will be in my supplement?
Besides iron and folic acid, a good prenatal supplement should contain:

vitamin C

vitamin D

B Vitamins thiamine, vitamin B6, riboflavin, niacin and B12

calcium

potassium

vitamin A

copper

pantothenic acid

zinc

vitamin E

Prenatal vitamins usually also contain a stool softener, such as docusate sodium, since large amounts of iron may cause constipation).