What Are Prenatal Vitamins?

Woman holding vitamins

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A prenatal vitamin is a multivitamin that is designed to give women the key nutrients they need when trying to conceive, during pregnancy, and while breastfeeding postpartum.

Why Prenatal Vitamins Are Important

Prenatal vitamins are like a nutrition safety net that help you maintain the vitamins and minerals your body needs to grow a healthy baby and sustain your pregnancy. They are not a substitute for a healthy diet, however, and work best when supported by good nutrition.

During pregnancy, your body has different needs, requiring more iron, calcium, B vitamins, vitamins A and C, and DHA (which is an omega-3 fatty acid).

Yet these needs are not exclusive to the nine months of pregnancy, so you would ideally begin taking prenatal vitamins a few months before you wanted to try to conceive. Taking them once you stop using birth control and begin to try in earnest would be beneficial.

One of the most important reasons to take prenatal vitamins prior to pregnancy is to get more folic acid. When taken prior to pregnancy, prenatal vitamins with folic acid can help drastically reduce the incidence of neural tube defects like spina bifida and anencephaly.

Since about half of all pregnancies are unplanned, a multivitamin—and, specifically, folic acid—is recommended for all women of childbearing age, even when they are not trying to get pregnant.

In addition to preventing neural tube defects, prenatal vitamins have also been found to reduce the risk of:

Types of Prenatal Vitamins

Prenatal vitamins can come in many forms (pills, capsules, gummies, and liquids), and they can be organic or vegan, as well as prescription or over-the-counter.

While there's no specific, standard formula for prenatal vitamins (discuss with your doctor or midwife which is best for you), most prenatal vitamins include some formulation of the following key nutrients for you and your baby:

  • Calcium: It is unlikely that a prenatal vitamin will contain all of the calcium you need. Pregnant women need 1,000 milligrams of calcium per day from all sources (food and supplements) as your baby develops its bones, teeth, and muscles.
  • DHA (docosahexaenoic acid): This omega-3 fatty acid is thought to protect against a number of pregnancy-related complications.
  • Folic acid: Pregnant women need at least 400 micrograms to 800 micrograms of folic acid daily to prevent birth defects known as neural tube defects, including spina bifida.
  • Iron: Your body needs twice as much iron as usual during pregnancy (27 milligrams per day) to build red cells to bring oxygen to the growing baby.

Other vitamins and minerals found in different types of prenatal vitamins might include:

  • Vitamin A: helps form healthy skin and eyes—too much vitamin A can cause birth defects, so be sure that you're using a prenatal vitamin or a multi-vitamin with under 10,000 international units (IU)
  • Vitamin C: helps you with tissue repair and wound healing and your baby with the development of bones and teeth
  • Vitamin D: helps the body absorb calcium and helps build the baby's bones and teeth
  • Iodine: helps the development of your baby's brain and nervous system
  • Zinc: helps to reduce preterm births

Tips for Taking Prenatal Vitamins

Depending on which prenatal vitamin you have chosen, you may take it once a day or multiple times per day. Follow the instructions provided to gain the maximum benefits. For example, many vitamins work best when taken with water and on an empty stomach. You may be advised not to eat for about an hour after taking the vitamin.

Choosing a Supplement

Whether you're trying to conceive, are pregnant, or breastfeeding, it's important to work with your doctor or midwife to determine which prenatal is best for you and your growing baby.

Perhaps the biggest determinant should be how well you tolerate the vitamin. You may need to try a few different types before finding one that does not have undesired side effects, such as nausea or constipation.

Prescription prenatal vitamins often have higher dosages than over-the-counter versions. This may make it easier to get the amounts of nutrients you need by taking fewer pills, but it can also increase the risk of side effects. A possible downside of over-the-counter vitamins is that they aren't as closely regulated, so the dosages stated on the label might not be as accurate.


Another factor may be the cost. You can get a prescription for a prenatal vitamin from most doctors or midwives, but over-the-counter brands may also be sufficient. If you have a prescription, your insurance may be more likely to pay, but check your plan since some insurers cover over-the-counter vitamins as well.

Even if insurance doesn't cover the over-the-counter version, consider whether the copayment on a prescription vitamin is more than the full cost of a vitamin off the shelf.

Seal of Approval

One of the safeguards to ensure purity, strength, and identity of supplements is independent, third-party testing. Look for seals of approval from these organizations:

These organizations provide quality testing, and if the product passes, they can display a seal of quality assurance that indicates that the product contains the ingredients listed on the label, and does not contain harmful levels of contaminants.

It is important to note, though, that these seals do not guarantee the product tested is safe or effective.

Possible Side Effects

Many women experience prenatal vitamin side effects, though sometimes these also be side effects of pregnancy. The following are some commonly reported side effects.


Switching to a lower dose of iron may reduce constipation. If you need to stay with a special brand or dose for a specific problem, like anemia, your practitioner may ask you to do the following to move things along and prevent constipation:

  • Drink more water.
  • Eat more fiber-rich foods.
  • Get more physical activity.

Skin Changes

Depending on the mix of nutrients found in a prenatal vitamin, some women may experience skin changes, including:

  • Bruising easily
  • Dry or peeling skin
  • Itchiness of the skin
  • Skin rash

Signs of an Allergic Reaction

If you experience any of the following skin rash signs, which may indicate an allergic reaction to your prenatal vitamin, call your healthcare professional immediately:

  • Cracked skin
  • Itching
  • Raised bumps
  • Redness
  • Scaling or flaking of skin
  • Swelling

Upset Stomach

Some women find that their stomach woes are due to prenatal vitamins rather than morning sickness, or that their vitamins make morning sickness worse. Diarrhea, dark stools, low appetite, and stomach cramps are also side effects of prenatal vitamins.

If you find that your stomach is upset when you take the vitamins, you may consider:

  • Cutting your prenatal vitamin in half and taking one part in the morning and the other at night
  • Taking your prenatal at a different time of day (such as at bedtime)
  • Trying a different prenatal vitamin

Do I Have to Take Prenatal Vitamins?

Some mothers choose not to take prenatal vitamins. They may stick to previous multivitamins, which should be done after clearing them with their practitioner. An example of things to look for would be the amount of vitamin A in your supplement. While evidence is not conclusive, some researchers believe that too much vitamin A can potentially cause birth defects.

Other mothers find that switching to children's vitamins eases some of the complaints about the prenatal vitamins. They may also come in a variety of styles. The chewable vitamins or gummy type vitamins are an option.

Whatever vitamins you take, it's recommended that they provide at least 400 micrograms of folic acid.

A Word From Verywell

While taking prenatal vitamins can not replace the benefits of a well-rounded diet, it can help ensure that you're getting the nutrients needed before, during, and after pregnancy. Talk to your physician or midwife to determine which type of prenatal vitamin will best suit you and and your baby.

4 Sources
Verywell Family uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
  1. Greenberg JA, Bell SJ, Guan Y, Yu YH. Folic acid supplementation and pregnancy: More than just neural tube defect prevention. Rev Obstet Gynecol. 2011;4(2):52-9.

  2. Centers for Disease Control and Prevention. Folic acid. April 11, 2018.

  3. American College of Obstetricians and Gynecologists. Nutrition during pregnancy. Updated June 2020.

  4. Linus Pauling Institute. Vitamin A. Micronutrient Information Center.

Additional Reading

By Robin Elise Weiss, PhD, MPH
Robin Elise Weiss, PhD, MPH is a professor, author, childbirth and postpartum educator, certified doula, and lactation counselor.