From the Guidelines
For women planning pregnancy, the recommended dose of folic acid is 400-800 micrograms (0.4-0.8 mg) daily, starting at least one month before conception and continuing through the first 12 weeks of pregnancy. This supplementation should be taken as part of a prenatal vitamin or as a standalone supplement. The evidence from the USPSTF recommendation statement 1 and the American Family Physician guidelines 1 supports the use of folic acid in preventing neural tube defects.
Key Considerations
- Women with higher risk factors, such as a previous pregnancy affected by neural tube defects, may need higher doses of 4 mg (4000 micrograms) daily, under medical supervision 1.
- Folic acid is crucial during early pregnancy as it helps prevent neural tube defects such as spina bifida and anencephaly, which form in the first 28 days after conception, often before a woman knows she's pregnant.
- Since approximately 50% of pregnancies are unplanned, it's recommended that all women of childbearing age who could potentially become pregnant take folic acid regularly.
- The supplement is water-soluble and best absorbed when taken with food.
Evidence Summary
The USPSTF found convincing evidence that supplements containing 0.4 to 0.8 mg (400 to 800 μg) of folic acid in the periconceptional period reduce the risk for neural tube defects 1. Additionally, the American Family Physician guidelines recommend folic acid supplementation of 400 mcg daily started before pregnancy and continued until six to 12 weeks postconception to reduce the rate of neural tube defects by nearly 75% 1.
From the FDA Drug Label
DOSAGE AND ADMINISTRATION ... The usual therapeutic dosage in adults and children (regardless of age) is up to 1 mg daily. ... 0.8 mg for pregnant and lactating women, but never less than 0. 1 mg/day. The recommended dose of folic acid to give preconception is not explicitly stated in the label, but for pregnant women it is 0.8 mg.
- Preconception dose is not directly mentioned.
- The dose for pregnant women is 0.8 mg 2 It is not possible to determine the dose for preconception based on this information.
From the Research
Folic Acid Dosage for Preconception
The recommended dosage of folic acid for preconception varies depending on the individual's risk factors.
- For women with low risk, a daily multivitamin supplement containing 0.4 mg of folic acid is recommended for at least 2 to 3 months before conception 3.
- For women with moderate risk, a daily multivitamin supplement containing 1.0 mg of folic acid is recommended, beginning at least 3 months before conception 3.
- For women with high risk, such as those who have had a previous pregnancy with a neural tube defect, a daily supplement with 4.0 mg of folic acid is recommended for at least 3 months before conception 3, 4.
- The American Academy of Pediatrics recommends that all women capable of becoming pregnant consume 400 micrograms of folic acid daily to prevent neural tube defects 4.
- A review of recent studies suggests that women of reproductive age should supplement with 0.4-1.0 mg of folic acid daily as part of their multivitamins 5.
Special Considerations
- Women who have had a previous pregnancy with a neural tube defect or have a family history of such defects may require higher doses of folic acid 3, 5.
- Women with certain medical conditions, such as diabetes or obesity, may also benefit from higher doses of folic acid 5.
- It is essential to note that folic acid supplementation should be taken in conjunction with a healthy diet and lifestyle 6, 3.