Prenatal Vitamins: Why they are important and how to choose the right one

June 27, 2022
| Created by Harmons

This article was written by Harmons Pharmacist Michelle Church, Pharm D

Prenatal vitamins are an essential way to supplement important vitamins and minerals for women trying to get pregnant or who are currently pregnant. Compared to regular daily vitamins, prenatal vitamins have more of some essential vitamins and minerals you specifically need during pregnancy. During pregnancy, your baby receives all the necessary nutrients directly from you. This means you may require more than you did prepregnancy. Multiples during pregnancy may also require more nutrients than a single-baby pregnancy. Women who are vegetarian, vegan, have food allergies or women who cannot eat certain foods may also need additional supplements. Always let your doctor know and they can assist you in finding the right supplements.

So, which nutrients are most important?

While all nutrients are important, these are the key nutrients important for your baby’s growth and development during pregnancy: folic acid, iron, calcium, vitamin D, and DHA.


  • This is a B vitamin that is essential to prevent neural tube defects and heart defects, as well as cleft lip and palate.
  • The recommended daily dose pre-pregnancy is 400mcg.
  • The dose during pregnancy is 600mcg. Make sure to read the label to verify the dose on your bottle. This dose may be higher if you are at high risk for a baby with a neural tube defect.


  • This is a mineral your body uses to make hemoglobin that helps carry oxygen to the rest of your body.
  • During pregnancy, your body requires more iron, often double, to make more blood so it can carry oxygen to your baby.
  • Your baby also needs iron for its own blood.
  • During pregnancy, the recommended dose is 27mg per day. Most prenatal vitamins contain this amount.


  • This is a mineral that helps your baby’s bones, teeth, heart, and muscles develop.
  • During pregnancy, the recommended dose is 1,000 mg per day.

Vitamin D

  • This helps your body absorb calcium. It also helps your baby’s bones and teeth grow.
  • During pregnancy, the recommended dose is 15 mcg (600 IU) per day


  • An omega-3 fatty acid that helps with baby’s brain and eye development
  • During pregnancy it is recommended women eat 8-12 ounces of seafood low in mercury (if not supplementing with DHA).
  • Not all prenatal vitamins contain DHA, so ask your doctor if they recommend this.

So, which prenatal vitamin is best?

There are over-the-counter options available as well as prescriptions. The American Pregnancy Association suggests that you make sure your vitamin contains the ones listed above as well as vitamin C, vitamin A, zinc, and iodine but they do not have to be prescription vitamins. Checking with your doctor for your specific needs is important. One potential benefit to having a prescription is your insurance may cover all or part of the cost. When choosing which OTC prenatal vitamins are best for you,  make sure you are checking the label to ensure all the essential vitamins are included.

When to start and how to take prenatal vitamins

It is recommended to start a prenatal vitamin at least one month before conception or as soon as you begin trying to get pregnant. This is important because the first 12 weeks of pregnancy are when the baby’s development is most critical.

Prenatal vitamins can be taken any time of day. They can be taken with or without food. However, some women can get an upset stomach and taking them with food can help prevent that. In addition to upset stomach, constipation can also be a concern. In this case drink plenty of fluids, try to eat more fiber, and include physical activity in your daily routine. If these things do not help you can ask your healthcare provider about adding a stool softener.

Prenatal vitamins post pregnancy

Prenatal vitamins are also important after giving birth to supplement important nutrients needed for breastfeeding mothers to prevent anemia and calcium deficiencies. It is recommended by the American Pregnancy Association that you continue prenatal vitamins for as long as you are breast feeding. In addition to your prenatal vitamin some health care providers will also recommend a higher dose of vitamin D. Check with your doctor for their recommendations.