Free family guide · Trying to conceive

Folic acid before pregnancy

CDC says neural tube defects form in the first weeks of pregnancy, often before a person knows they are pregnant.[1]

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Sources on this page: CDC; USPSTF; NICHD; ACOG; NHS

This page shares what health organizations say. It is not medical advice. It is general information. Talk to your doctor, midwife or pediatrician about your own situation.

In an emergency, call 911.

How much

Sources differ

Sources give the daily amount in slightly different ways:[2][1][3][4][5]

  • The USPSTF advises a supplement with 0.4 to 0.8 mg (400 to 800 mcg) a day.[2]
  • CDC says anyone who could become pregnant should get 400 mcg of folic acid every day.[1]
  • NICHD advises at least 400 mcg before trying to conceive.[3]
  • ACOG says to take a prenatal vitamin with at least 400 mcg, and that pregnant women should get 600 mcg a day from all sources.[4]
  • The NHS advises 400 micrograms a day.[5]

ACOG says only folic acid, not other forms of folate, is proven to prevent neural tube defects.[4]

ACOG says not to take more than the recommended daily dose of prenatal vitamins.[4]

When to start and stop

Sources differ

Sources give slightly different timing:[2][6][5]

  • The USPSTF says to start at least 1 month before conception and continue through the first 2 to 3 months of pregnancy.[2]
  • ACOG says to start at least 1 month before pregnancy and continue through the first 12 weeks.[6]
  • The NHS says to take it until at least week 12.[5]

CDC says neural tube defects form in the first weeks of pregnancy, often before a person knows they are pregnant.[1]

If you had a pregnancy affected by a neural tube defect

CDC lists 4,000 mcg a day for people who had a pregnancy affected by a neural tube defect, after talking with a doctor.[1] ACOG says they may need 4 mg a day, starting at least 3 months before pregnancy.[6]

The USPSTF says its advice does not cover people at very high risk, who should talk with their clinician.[2]

Questions families ask

How much folic acid should I take before pregnancy?

CDC says anyone who could become pregnant should get 400 mcg of folic acid every day.[1] The USPSTF advises 0.4 to 0.8 mg (400 to 800 mcg) a day.[2]

Why 400 mcg before and 600 mcg during pregnancy?

ACOG says to take a prenatal vitamin with at least 400 mcg plus folate-rich foods, for a total of 600 mcg a day in pregnancy.[4]

Is it too late if I am already pregnant?

The USPSTF advises continuing a daily supplement through the first 2 to 3 months of pregnancy.[2] CDC says to talk to your providers before you start or stop any medicine.[7]

Free from UpOnly Learning. Written for families of every faith. No outside ads and no affiliate links. Every fact on this page comes from the sources listed below. How we source and review these pages

Updated 2026-10-24: first published.

Sources

All sources were opened and checked on the date shown.

  1. Centers for Disease Control and Prevention. About Folic Acid. Checked October 24, 2026.
  2. US Preventive Services Task Force. Folic Acid Supplementation to Prevent Neural Tube Defects: Preventive Medication. Checked October 24, 2026.
  3. Eunice Kennedy Shriver National Institute of Child Health and Human Development (NIH). Can you promote a healthy pregnancy before getting pregnant?. Checked October 24, 2026.
  4. American College of Obstetricians and Gynecologists. Healthy Eating During Pregnancy. Checked October 24, 2026.
  5. NHS (United Kingdom). 4 weeks pregnant guide. Checked October 24, 2026.
  6. American College of Obstetricians and Gynecologists. Good Health Before Pregnancy: Prepregnancy Care. Checked October 24, 2026.
  7. Centers for Disease Control and Prevention. Medicine and Pregnancy: An Overview. Checked October 24, 2026.