Pregnancy changes nutrient needs in a few important ways, and a prenatal vitamin is one of the simplest things you can do to support a healthy pregnancy. But prenatal vitamins vary a lot. Some are missing key nutrients, some contain unnecessary extras, and prices range widely. Here is what to look for, based on the recommendations of major health organizations. Your own doctor or midwife may adjust these based on your health.
When to start
Ideally, start taking a supplement with folic acid at least one month before you try to conceive. Many pregnancies are unplanned, and the baby's brain and spinal cord form in the first few weeks, often before people know they are pregnant. That is why the CDC recommends that anyone who could become pregnant get 400 micrograms of folic acid every day.
The key nutrients
Folic acid (folate)
Folic acid helps prevent serious birth defects of the brain and spine called neural tube defects. Most prenatal vitamins contain 400 to 800 micrograms. Some people need more, such as those who have had a previous pregnancy affected by a neural tube defect, and their doctor will advise a higher dose. Labels may list folate as micrograms DFE (dietary folate equivalents). See our folate page.
Iron
Blood volume increases dramatically during pregnancy, and iron needs nearly double. The recommended amount in pregnancy is 27 mg a day. Many prenatal vitamins contain around this amount. If iron upsets your stomach, talk to your provider about options. See iron supplements: who needs them.
Iodine
Iodine is important for the baby's brain development. The American Thyroid Association recommends that pregnant and breastfeeding people take a supplement with 150 micrograms of iodine a day. Surprisingly, many prenatal vitamins do not contain any. Check the label.
Vitamin D
Important for bone health for both parent and baby. Many prenatal vitamins contain 400 to 1,000 IU. Your provider may test your level and recommend more if you are low.
Choline
Choline supports the baby's brain and spinal cord development. The recommended amount in pregnancy is 450 mg a day, but most prenatal vitamins contain little or none. Eggs are an excellent source. If you do not eat eggs, ask about a supplement.
DHA (omega-3)
DHA supports the baby's brain and eye development. A common recommendation is about 200 to 300 mg of DHA a day during pregnancy, from fish or supplements. Many prenatal vitamins come with a separate DHA softgel. See DHA and your child's brain.
Calcium
Needs are the same as for other adults, 1,000 mg a day for most, but it is important to meet them. Most prenatal vitamins contain only a little calcium because it is bulky, so food sources matter.
Vitamin B12
Especially important for vegans and vegetarians.
What to avoid or limit
- Too much vitamin A. High amounts of preformed vitamin A (retinol) can cause birth defects. Prenatal vitamins usually contain safe amounts or use beta-carotene. Avoid extra vitamin A supplements and, during pregnancy, avoid large amounts of liver.
- Herbal supplements, unless your provider approves them. Many have not been studied for safety in pregnancy.
- Doubling up. Do not take a prenatal plus a regular multivitamin unless advised.
- Unproven extras that drive up the price.
Choosing a prenatal vitamin
- Check for folic acid (400 to 800 mcg), iron (about 27 mg) and iodine (150 mcg).
- Look for vitamin D and, ideally, choline.
- Consider a separate DHA supplement if the prenatal does not include it and you rarely eat fish.
- Look for third-party testing. See what third-party tested means.
- Compare price per daily dose. A store-brand prenatal can be just as good as an expensive one.
- Choose a format you can tolerate. If large pills make you nauseous, try smaller tablets taken twice a day, chewables or taking it at night with a snack.
Food still matters
A prenatal vitamin is a safety net, not a replacement for good food. Aim for plenty of fruits, vegetables, whole grains, lean protein, dairy or fortified alternatives, and low-mercury fish. Follow food safety guidance during pregnancy, such as avoiding unpasteurized dairy and undercooked meat.
The bottom line
Start folic acid before pregnancy if you can. Choose a prenatal vitamin with folic acid, iron, iodine and vitamin D, and pay attention to choline and DHA. Avoid extra vitamin A and unapproved herbs, and talk to your doctor or midwife about your individual needs. Our women's wellness hub has more resources.