Prenatal Vitamins: What You Need to Know

A prenatal vitamin helps fill nutritional gaps during pregnancy. While a balanced diet is the best source of nutrients, a prenatal vitamin provides extra support for the nutrients that are most critical during pregnancy.

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Key Nutrients in a Prenatal Vitamin

Folic Acid (400-800 mcg)

Folic acid is the synthetic form of folate, a B vitamin that reduces the risk of neural tube defects (NTDs) such as spina bifida. The neural tube forms and closes by week 28, often before many women know they are pregnant. This is why ACOG recommends that all women who could become pregnant take 400-800 mcg of folic acid daily.

Iron (27 mg)

Iron supports the increased blood volume during pregnancy and helps prevent anemia. Your blood volume increases by about 50% during pregnancy, and your baby is also building their own iron stores.

Calcium (1,000 mg)

Calcium supports the development of the baby's bones and teeth. If you do not get enough calcium in your diet, your body will take calcium from your bones to support the baby.

Vitamin D (600 IU)

Vitamin D supports calcium absorption and bone health. It also plays a role in immune function. Many women are deficient in vitamin D, especially those who live in northern climates or have darker skin.

DHA (200-300 mg)

DHA (docosahexaenoic acid) is an omega-3 fatty acid that supports the baby's brain and eye development. It is found in fatty fish and algae-based supplements.

Iodine (220 mcg)

Iodine is essential for the baby's thyroid function and brain development. Mild iodine deficiency is common in the United States.

Choline (450 mg)

Choline supports the baby's brain development and helps prevent neural tube defects. Most prenatal vitamins do not contain enough choline, so dietary sources (eggs, meat, fish) are important.

When to Start Taking Prenatal Vitamins

ACOG recommends starting a prenatal vitamin at least one month before conception. Because many pregnancies are unplanned, it is best for all women who could become pregnant to take a prenatal vitamin daily.

If you are already pregnant, start taking a prenatal vitamin as soon as you find out. The first trimester is a critical period for neural tube development.

Choosing a Prenatal Vitamin

Not all prenatal vitamins are created equal. Here is what to look for:

Folic acid: 400-800 mcg
Iron: 27 mg
Calcium: 200-300 mg (most women need additional calcium from diet or a separate supplement)
Vitamin D: 600 IU
DHA: 200-300 mg
Iodine: 220 mcg
Choline: 450 mg (often not included in prenatal vitamins)

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Always discuss supplements with your clinician before starting them. Some supplements may interact with medications or may not be appropriate for your specific situation.

Foods to Focus On

A prenatal vitamin supplements a healthy diet — it does not replace one. Focus on:

Leafy greens: Folate, calcium, iron
Eggs: Choline, protein, vitamin D
Fatty fish: DHA, vitamin D (limit to 2-3 servings per week)
Lean meat: Iron, protein, choline
Dairy: Calcium, vitamin D, protein
Whole grains: Iron, B vitamins, fiber
Legumes: Folate, iron, protein, fiber

When to Call Your Clinician

Contact your healthcare provider if:

You cannot tolerate your prenatal vitamin (nausea, constipation)
You have questions about which supplements to take
You have a medical condition that affects your nutritional needs

Not medical advice: This guide is for informational purposes only. It does not replace professional medical advice, diagnosis, or treatment. Always consult your own clinician.