Why folic acid, iron and fish top pregnancy nutrition advice

If you are pregnant, nursing or planning a pregnancy, a few pieces of guidance come up again and again. This guide covers what the sources we reviewed say about folic acid, prenatal supplements, iron and fish. It does not cover everything, so it is a starting point for a talk with your doctor, midwife or a registered dietitian.

Folic acid before and during early pregnancy

Folic acid is the form of folate, a B vitamin, that is found in supplements. The US Centers for Disease Control and Prevention (CDC) recommends that all women capable of becoming pregnant get 400 micrograms (mcg) of folic acid daily.

The CDC says many studies show that taking folic acid before and during early pregnancy lowers the chance of neural tube defects. These are serious birth defects of the baby's brain and spine.

The CDC's clinician page also lists a much higher amount, 4,000 mcg daily, for women planning another pregnancy. It says this should start one month before trying to conceive and continue through the first 3 months of pregnancy. The excerpt we reviewed does not say who this applies to, so talk with your clinician about the right amount for you.

Prenatal supplements

The National Institutes of Health's Office of Dietary Supplements, summarizing the 2020–2025 Dietary Guidelines for Americans, says most health care providers recommend a daily prenatal supplement for women who are pregnant or planning to become pregnant. That comes in addition to a healthy dietary pattern.

The guidelines add that prenatal supplements may be especially important for meeting folate/folic acid, iron, iodine and vitamin D needs.

Iron

The sources give different figures. A Linus Pauling Institute summary says the CDC recommends adequate dietary iron plus iron supplementation of 30 mg a day, starting at the first prenatal visit. A University of Georgia extension publication says it is important for pregnant women to take an iron supplement to meet a daily requirement of 27 mg. Ask your doctor what amount is right for you.

Fish

The American College of Obstetricians and Gynecologists (ACOG) says you should eat two or three servings of fish or shellfish per week before getting pregnant, while pregnant and while breastfeeding. The excerpt we reviewed does not say which fish to choose or limit, so check ACOG's full page or ask your care team.

Why it matters

The CDC says taking folic acid before and during early pregnancy lowers the chance of neural tube defects, which is one reason timing matters. Your own needs depend on your health, so confirm supplements and amounts with your doctor or a registered dietitian.