A lot of people assume prenatal vitamins are something you start after a positive pregnancy test. But public health experts actually recommend thinking about one key nutrient well before then. Here's what the guidance says, in plain language.
The short answer: before pregnancy
The U.S. Centers for Disease Control and Prevention (CDC) recommends that all women who could become pregnant get 400 micrograms (mcg) of folic acid every day, whether or not they're actively planning a pregnancy.
The U.S. Preventive Services Task Force (USPSTF), an independent panel of national experts, reaffirmed a similar recommendation in 2023. It advises a daily supplement with 400 to 800 mcg of folic acid for anyone planning to or able to become pregnant, starting at least one month before conception and continuing through the first two to three months of pregnancy.
Why the timing matters
Folic acid is a form of folate, a B vitamin. It's important for the early development of the baby's neural tube, which becomes the brain and spine.
The CDC explains that neural tube defects happen in the first few weeks of pregnancy, often before a person knows they're pregnant. The USPSTF notes that the neural tube closes about 26 to 28 days after fertilization. That's why the recommendation starts before pregnancy rather than after.
And because many pregnancies aren't planned, the CDC's advice applies to everyone who could become pregnant, not just those who are trying.
What about the rest of a prenatal?
Folic acid gets the most attention, but pregnancy increases your need for several nutrients. The NIH Office of Dietary Supplements (ODS) notes that the American College of Obstetricians and Gynecologists (ACOG) recommends a daily prenatal supplement alongside a healthy diet during pregnancy. Nutrients that become especially important include:
- Iron. The recommended amount rises to 27 mg per day during pregnancy.
- Iodine, which is important for the baby's brain development. The ODS notes that many prenatal supplements don't contain it.
- Choline, a nutrient most pregnant women don't get enough of, according to the ODS.
- Vitamin D and omega-3 fatty acids (DHA), which also support fetal development.
The ODS also points out that prenatal supplements vary a lot. Some leave out iodine or choline, and gummy versions often lack iron and calcium. It's worth reading labels and asking your provider whether your prenatal covers what you need.
Folic acid vs. methylfolate: what to know
You may see prenatal vitamins that contain methylfolate (also called 5-MTHF or L-methylfolate) instead of, or in addition to, folic acid. Here's an honest look at what the experts say.
- Methylfolate is an active form of folate. The ODS notes that its bioavailability in supplements is the same as or greater than folic acid.
- However, the CDC states that folic acid is the only type of folate shown to help prevent neural tube defects. The CDC and USPSTF recommendations are written specifically for folic acid.
- Some people hear that if they have an MTHFR gene variant, they should avoid folic acid. The CDC says this is not true: people with an MTHFR variant can process all types of folate, including folic acid.
The bottom line: if you're considering a prenatal with methylfolate, it's a good idea to talk with your provider about whether it meets your needs, and whether you should also be getting folic acid.
Safety notes
- Talk to your provider first. Your doctor, midwife, or pharmacist can help you choose a prenatal and tell you if you need a different amount of any nutrient.
- Some people need more folic acid. The CDC notes that people who've had a previous pregnancy affected by a neural tube defect may need a much higher dose, under a provider's direction.
- Certain medications matter. The USPSTF notes its general recommendation doesn't apply to people taking certain medications, such as some anti-seizure drugs or methotrexate. Your provider will guide you.
- More isn't better. The ODS sets an upper limit of 1,000 mcg per day for folic acid from supplements and fortified foods, and notes that very high folate intake can mask a vitamin B12 deficiency. Too much preformed vitamin A can also be harmful during pregnancy. Avoid doubling up on multivitamins unless your provider recommends it.
The takeaway
If you could become pregnant, the time to start thinking about a prenatal, and especially folic acid, is now, not later. CDC and USPSTF guidance recommends at least 400 mcg of folic acid daily, starting at least a month before conception. A good prenatal also covers nutrients like iron, iodine, and choline. Your provider is the best partner in choosing what's right for you.
Related from Hami
Hami Prenatal Multivitamin (coming soon). Talk with your healthcare provider before starting any new supplement.
Sources
- Centers for Disease Control and Prevention. About Folic Acid.
- U.S. Preventive Services Task Force. Folic Acid Supplementation to Prevent Neural Tube Defects: Preventive Medication (2023).
- Centers for Disease Control and Prevention. MTHFR Gene Variant and Folic Acid Facts.
- NIH Office of Dietary Supplements. Folate: Fact Sheet for Health Professionals.
- NIH Office of Dietary Supplements. Dietary Supplements and Life Stages: Pregnancy.
*These statements have not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure, or prevent any disease. This article is for educational purposes only and is not medical advice. Talk with your healthcare provider before starting any supplement.