All About Prenatal Vitamins — Your Questions Answered

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If you've got baby on the brain, you should start taking a prenatal vitamin three months before you begin trying to get pregnant, if possible. "The egg starts maturing about three months before it's released, and it's critical that the proper nutrients are present during the earliest stages," says OB-GYN and reproductive endocrinologist Robert Greene, M.D., F.A.C.O.G., a fertility specialist at cny Fertility center in Syracuse, N.Y.

If you think you're pregnant and are not taking a supplement, don't wait until your first appointment for a prescription because you will have missed a crucial developmental period for your baby:

"Neural-tube defects [such as spina bifida] happen in the first four to six weeks of pregnancy," says Sudeep Kukreja, M.D., associate director of the neonatal intensive care unit at Children's Hospital of Orange County in Orange, Calif. So start taking an over-the-counter folic acid supplement with 600 micrograms right away.

Still have questions when it comes to taking prenatal vitamins? You're not alone. We tackled the most common questions expecting moms have about prenatal vitamins to get you guidance from the experts.

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Which vitamins and minerals are most important and why?

"The three most important nutrients, based on very good research, are folic acid, iron and calcium," says Kukreja. Folic acid helps prevent neural-tube defects; iron is important for the delivery of oxygen to the baby and prevents anemia in the mom; and calcium helps build your baby's bones and prevents bone loss in the mother.

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Are all prenatal vitamins pretty much the same?

No. Prescription vitamins are regulated by the Food and Drug administration, but they're not required to contain certain nutrients. "There are many different formulations available, with different concentrations of each nutrient," says Kukreja. Some have a little of everything; others contain only a handful of nutrients. If you have special health considerations, your OB may suggest a supplement with added nutrients to meet your needs.

Can I take an over-the-counter or organic prenatal vitamin?

There's nothing wrong with taking over-the-counter vitamins as long as they have a USP (U.S. Pharmacopeia) seal or NSF International certification; these organizations monitor supplement quality. "We do have concerns about pills that contain certain herbs and those that may contain too much of a certain nutrient, like vitamin A, which can adversely affect the fetus' development," says Ashlesha Dayal, M.D., an associate professor of obstetrics and gynecology at the Montefiore Medical Center in Bronx, N.Y. "Take the bottle to your obstetrician to make sure that all the ingredients are safe," Kukreja adds.

What should I do if I have morning sickness and am throwing up?

"Try to take the vitamin before you go to bed at night, so you can sleep through the nausea," says Bronx, N.Y.-based OB-GYN Ashlesha Dayal, M.D.

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Do I need to take anything in addition to my prenatal vitamin?

"Supplement with calcium if your prenatal doesn't contain enough," says Kukreja. Most don't because adding too much calcium to a multivitamin makes it unstable. Pregnant women need 1,000 milligrams a day; many supplements only contain 150 milligrams to 250 milligrams. You can take a tums tablet daily to supplement it.

In addition, many pregnant women don't get the institute of medicine's recommendation for 600 IUs of vitamin D per day. But most prenatal vitamin formulations contain 400 IU, and this should be adequate when combined with a healthy diet, Dayal says. The March of Dimes also recommends that pregnant women get at least 200 milligrams of DHA daily. Found in fish and some plant-based, vegetarian sources, DHA is an omega-3 fatty acid that's essential to fetal brain and eye development, Dayal says. Many prenatals contain DHA, but you also can take fish oil capsules; they're mercury-free.

I'm a vegetarian. Should I be taking any additional supplements?

"Because [strict] vegetarians are not consuming animal products, the nutrients they tend to need are vitamin B12, zinc, iron and omega-3 fatty acids like DHA," says greene. "Look for supplements that contain these vitamins plus DHA from algae, a vegetarian source, rather than from fish."

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Is it bad if you don’t take your prenatal vitamins during your pregnancy?

The best way to stay healthy during your pregnancy is to eat right and maintain a healthy weight gain. Yes prenatal vitamins are an important part of your pregnancy nutrition, but they are never a subtitute for a healty well balanced diet. If you forget your vitamins once in a while do not panic...and do not "double up" because they may make you feel sick or increase constipation. I usually recommend that my patients put any "daily medicine" in a place they go every day...such as next to their toothbrushes, hairdryers, car keys, etc. Sometimes you can even set a daily reminder or alarm on your cell phone so you can remember to take your vitamins.

Can I take regular vitamins until I get my prenatal vitamins refilled?

It is fine to take a regular, over-the-counter multivitamin for a short time until you get your prescription refilled. This would not be advisable for long periods of time because prenatal vitamins have different amounts of certain vitamins and minerals that are specially formulated for pregnancy. For example, there is more iron in a prenatal vitamin than in a regular multivitamin. And, most prescription prenatals have DHA, a fatty acid thought to be important in fetal eye and brain growth, whereas many over the counter formulations do not. You can also ask your practitioner to give you some samples to help you temporarily.