Updated on March 19, 2025.
For many people, eating a healthy, balanced diet is the best way to get the vitamins and minerals your body needs. But even a healthy diet might be missing some key nutrients.
The stakes are even higher when you’re pregnant or trying to become pregnant. At that point, it’s critical to fill those gaps with a prenatal vitamin. Nutrients found in prenatal vitamins—like folic acid, iron, calcium, and vitamin D, among others—are necessary for the growth and development of a fetus. Many studies have linked them to reduced risk of birth defects.
It’s important to talk to your healthcare provider (HCP) before starting any new vitamin or supplement, particularly when you’re pregnant, breastfeeding, or trying to conceive. Your HCP will be able to recommend the best prenatal based on your pregnancy and health history.
With that in mind, here’s what to know about these vital vitamins.
What essential ingredients do prenatal vitamins have?
Like a daily multivitamin, a prenatal vitamin can provide nutrients your everyday diet might lack. The major difference? Prenatal vitamins typically contain higher amounts of the vitamins and minerals essential to a growing fetus—specifically, folic acid and iron.
“Folic acid is important in the nerve development of the fetus, protecting against neural tube defects, like spina bifida,” explains Meghan J. Freund, MD, an OBGYN in Green Bay, Wisconsin. “Iron helps with growth and development of the fetus, and also helps mom. Because blood volume expands during pregnancy, a lot of pregnant patients become anemic. You need a prenatal because a lot of over-the-counter multivitamins don’t even contain iron.”
Folic acid
Adequate intake of folic acid has been linked to reduced risk of spina bifida, a birth defect affecting the spine and spinal cord, and anencephaly, the underdevelopment of the brain and skull.
Supplements with folic acid are recommended because it’s difficult to get enough of this key vitamin from food alone. During pregnancy, you need 600 micrograms of folic acid daily, according to the American College of Obstetricians and Gynecologists (ACOG).
If you’re trying to get pregnant, start taking a daily prenatal vitamin with at least 400 micrograms at least one month before you begin. Continue to take it during the first 12 weeks of pregnancy. This preventive step is important because birth defects affecting the spine and brain usually occur within the first month after conception—often before a person even knows they’re pregnant.
In addition to taking a prenatal vitamin, you can boost your daily intake of folic acid by eating foods such as:
- Leafy greens, like spinach
- Enriched pastas, rice, cereals, and bread
- Nuts
- Citrus fruits
- Legumes, like beans, peas, lentils
- Avocado
- Eggs
- Bananas
Iron
Iron, a mineral that helps red blood cells transport oxygen to the rest of the body, is another key nutrient in prenatal vitamins.
Not getting enough iron during pregnancy has been linked to low birth weight, premature birth, and maternal and infant mortality. It’s also linked to maternal anemia, which occurs when there aren’t enough red blood cells to carry oxygen to the body’s tissues. Anemia can cause symptoms like fatigue, weakness, shortness of breath, dizziness, headaches, and chest pain. Although the condition is highly treatable when caught early, it may become dangerous if left untreated.
Due to the increase in blood volume during pregnancy, pregnant people should aim for 27 milligrams of iron per day, according to ACOG. When breastfeeding, adults need 9 milligrams of iron daily, while people 14 to 18 years old require 10 milligrams.
In addition to taking a prenatal vitamin, you can enjoy iron-rich foods like:
- Iron-fortified cereals and grains
- Beef and chicken
- Tuna
- Tofu
- Lentils and beans
- Spinach
To know: Although people who eat a plant-based diet can still choose from a variety of plant foods with iron, the body absorbs two to three times more iron from animal sources than from plants.
Foods that contain vitamin C can help the body absorb iron more efficiently. Pair foods containing iron with fruits and veggies like strawberries, oranges, bell peppers, and tomatoes.
Who should take prenatal vitamins?
Prenatal vitamins are recommended for all pregnant people and people who are planning to become pregnant.
They may also be important post-pregnancy. People with restrictive diets or those who are breastfeeding may not get adequate nutrients through diet alone. Your HCP may recommend that you continue a prenatal vitamin or switch to a multivitamin while breastfeeding, depending on your daily nutritional needs.
Groups who may need to take higher than usual amounts of some nutrients already in prenatal vitamins are:
- People who have already given birth to a baby with a neural tube defect
- Those with a family history of spina bifida
- Those taking anti-epileptic medicines
- Populations with chronic conditions linked to an unbalanced diet
Speak with your HCP if you fall into any of these categories.
Additionally, pregnant people with special diets, such as vegetarian or gluten-free, should talk with an HCP or dietitian to ensure their dietary needs are being met during their pregnancy.
What should I look for when shopping for a prenatal vitamin?
Over-the-counter prenatal vitamins are widely available in pharmacies, drugstores, and grocery stores and through online retailers. Your HCP can also provide a prescription. If you have a family history of neural tube defects, have given birth to a child with a neural tube defect, or have a medical condition like anemia, you may be advised to take additional supplements to help support your pregnancy.
When choosing a prenatal vitamin, look for products that are high in calcium and vitamin D in addition to folic acid and iron. These nutrients play a vital role in the development of your baby’s skeletal system and are especially important during the second and third trimesters, says Freund. When paired with a prenatal, you can also increase your intake of foods that are high in calcium and vitamin D, like fortified dairy products, fortified orange juice, fatty fish, egg yolks, kale, and broccoli.
Some prenatal vitamins also have DHA, a type of omega-3 fatty acid. DHA is thought to help fetal brain and eye development. Not all prenatal vitamins have DHA, but it may be beneficial to seek one, especially if you do not eat fish or other foods high in omega-3 fatty acids.
Be aware that not all prenatal supplements are created equal. The amount of each nutrient contained in a prenatal vitamin can vary by brand, and in some cases may be outside of the recommended levels. In fact, in 2023, the U.S. Food and Drug Administration (FDA) examined 12 prenatal vitamins and found that 11 contained at least one nutrient in a different amount than noted on the label. One vitamin had such a high amount of folic acid that experts proposed it could cause health issues based on current guidelines.
Overall, however, vitamins and prenatal supplements help to support healthy pregnancy, and without the use of supplements, pregnant people would likely not take in the recommended amount of key nutrients. Many experts suggest that guidance should be provided to pregnant people about selecting a supplement with a responsible formulation, along with nutritional and dietary recommendations.
Are there side effects to prenatal vitamins?
According to Freund, most people don’t experience serious side effects from prenatal vitamins. “Sometimes people have trouble swallowing pills,” she says. “Or, if they have bad nausea, especially in the first trimester, they may have an aversion to their prenatal vitamins.”
Other people may experience constipation, often due to the high amount of iron in prenatal vitamins. Drinking plenty of fluids, exercising, taking your vitamin at night, and adding fiber to your diet may provide relief.
Some people, however, may still experience discomfort. “For those patients, we recommend prenatal gummy vitamins,” Freund says. Since gummy vitamins often lack calcium and iron, people may need to take in additional amounts of those nutrients within their diet or through other supplements.
Note that it is possible to take too many vitamins, which could cause vitamin toxicity. It occurs when an overload of a particular nutrient leads to health issues, which may include concerning symptoms, damage to organs, and even death. Although rare, this risk is greater for iron, calcium, vitamins A and D, and folic acid.
If you’re not pregnant or planning to become pregnant, avoid taking prenatal vitamins. Over time, the extra nutrients in prenatal formulas can be too much for your body. An excess of iron, for example, can affect your zinc levels, trigger stomach issues, or cause other serious health problems. Oftentimes, healthy adults who are not trying to get pregnant can get needed nutrients from food.
Remember: If you’re pregnant or trying to become pregnant, a prenatal vitamin should be a part of your daily routine. If you’re not sure which prenatal is right for you or have any questions about your diet, talk to your HCP. Bring up any supplements you already take. Keep in mind that a vitamin or supplement works best as an extra tool along with a complete and healthy diet. Use them only as directed, typically once daily.
“Having a healthy, balanced diet and staying adequately hydrated will lay the groundwork for a healthy, happy baby,” says Freund.
