Folic acid before and in early pregnancy
The USPSTF recommends that anyone planning to or who could become pregnant take a daily supplement with 0.4 to 0.8 mg (400 to 800 mcg) of folic acid (grade A, 2023). It helps prevent neural tube defects, birth defects of the brain and spinal cord. (USPSTF, 2023)
The timing matters: the critical period starts at least 1 month before conception, and nearly half of US pregnancies are unplanned. (USPSTF, 2023) If you had a pregnancy with a neural tube defect, or take a medicine that affects folic acid, ask your doctor: this advice is not for you.
- USPSTF grade
- A
- Who
- Anyone who could become pregnant
- How much
- 0.4 to 0.8 mg (400 to 800 mcg) a day
- When
- From 1 month before conception to 2 to 3 months in
Folic acid by stage
| Stage | What the USPSTF says |
|---|---|
| Could become pregnant, at any age | A daily supplement or multivitamin with 0.4 to 0.8 mg (400 to 800 mcg) of folic acid |
| Planning a pregnancy | Start at least 1 month before trying to conceive |
| First 2 to 3 months of pregnancy | Keep taking it every day |
| A past pregnancy with a neural tube defect, a strong family history, or a medicine that blocks folic acid | Not covered by this recommendation: ask your doctor |
Because nearly half of pregnancies in the US are unplanned, many people do not know they are pregnant during the critical weeks. That is why the USPSTF advice covers everyone who could become pregnant, not only those planning to. (USPSTF, 2023)
The CDC says all women who could become pregnant should get 400 mcg of folic acid every day, from vitamins and from fortified foods such as breakfast cereals, and that people thinking about pregnancy should start at least 1 month before conception. (CDC, 2026)
As summarized by the USPSTF, ACOG, the AAFP and the AAP recommend 0.4 mg (400 mcg) a day for people at average risk who plan to become pregnant. The USPSTF range starts at that amount and goes up to 0.8 mg. (USPSTF, 2023)
Questions people ask
How much folic acid should I take before pregnancy?
The USPSTF recommends a daily supplement with 0.4 to 0.8 mg (400 to 800 mcg) of folic acid for anyone planning to or who could become pregnant. The CDC says 400 mcg a day. (USPSTF, 2023) (CDC, 2026)
When should I start taking folic acid?
At least 1 month before conception, and keep going through the first 2 to 3 months of pregnancy. Since many pregnancies are unplanned, the USPSTF advice applies to anyone who could become pregnant. (USPSTF, 2023)
Can I get folic acid from food?
The CDC says folic acid comes from vitamins and from fortified foods such as breakfast cereals. The USPSTF recommendation is specifically a daily supplement or multivitamin. (CDC, 2026) (USPSTF, 2023)
What if I had a pregnancy with a neural tube defect?
This recommendation does not apply to you, nor to people at very high risk from family history or a medicine that blocks folic acid. Talk to your doctor before trying to conceive. (USPSTF, 2023)
This page explains what the guidelines say. It cannot tell you what is right for you: talk to your doctor.