Wonder if you need to take prenatal vitamins? Which brand is best? Or what to do if they make you queasy? Get answers to these questions and more.

By Mayo Clinic Staff

A healthy diet is the best way to get the vitamins and minerals you need — but even if you eat a healthy diet, you might fall short on key nutrients. If you're pregnant or hoping to conceive, prenatal vitamins can help fill any gaps.

Prenatal vitamins typically contain more folic acid and iron than do standard adult multivitamins. Here's why:

  • Folic acid helps prevent neural tube defects. These defects are serious abnormalities of the brain and spinal cord.
  • Iron supports the baby's growth and development. Iron also helps prevent anemia, a condition in which blood lacks adequate healthy red blood cells.

In addition, some research suggests that prenatal vitamins decrease the risk of low birth weight.

Standard prenatal vitamins don't include omega-3 fatty acids, which might help promote a baby's brain development. If you're unable or choose not to eat fish or other foods high in omega-3 fatty acids, your health care provider might recommend omega-3 fatty acid supplements in addition to prenatal vitamins.

Calcium and vitamin D are important as well — especially during the third trimester, when your baby's bones are rapidly growing and strengthening. In addition to your prenatal vitamin, drink vitamin D-fortified low-fat milk or other calcium-rich foods containing vitamin D. If you don't drink milk or eat calcium-rich foods, talk to your health care provider about calcium and vitamin D supplements.

Prenatal vitamins are available over-the-counter in nearly any pharmacy. Your health care provider might recommend a specific brand of prenatal vitamins or leave the choice up to you.

Generally, look for a prenatal vitamin that contains:

  • Folic acid — 400 to 800 micrograms
  • Calcium — 250 milligrams
  • Iron — 30 milligrams
  • Vitamin C — 50 milligrams
  • Zinc — 15 milligrams
  • Copper — 2 milligrams
  • Vitamin B-6 — 2 milligrams
  • Vitamin D — 400 international units

Remember, prenatal vitamins are a complement to a healthy diet — not a substitute for good nutrition. Prenatal vitamins won't necessarily meet 100 percent of your vitamin and mineral needs. In addition, your health care provider might suggest higher doses of certain nutrients depending on the circumstances. For example, if you've given birth to a baby who has a neural tube defect, your health care provider might recommend a separate supplement containing a higher dose of folic acid — such as 4 milligrams (4,000 micrograms) — before and during any subsequent pregnancies.

Ideally, you'll start taking prenatal vitamins before conception. The baby's neural tube, which becomes the brain and spinal cord, develops during the first month of pregnancy — perhaps before you even know that you're pregnant.

If you have trouble swallowing standard prenatal vitamins, you might try the chewable variety — or ask your health care provider about other options.

It's best to take prenatal vitamins throughout your entire pregnancy. Your health care provider might recommend continuing to take prenatal vitamins after the baby is born — especially if you're breast-feeding.

Some women feel queasy after taking prenatal vitamins. If this happens to you, take your prenatal vitamin with a snack or before you go to bed at night.

In other cases, the iron in prenatal vitamins contributes to constipation. To prevent constipation:

  • Drink plenty of fluids
  • Include more fiber in your diet
  • Include physical activity in your daily routine, as long as you have your health care provider's OK
  • Ask your health care provider about using a stool softener

If these tips don't seem to help, ask your health care provider about other options. He or she might recommend another type of prenatal vitamin or separate folic acid, calcium with vitamin D, and iron supplements.

Apr. 20, 2012