From the Guidelines
The recommended daily intake of folic acid during pregnancy is 400-800 micrograms (0.4-0.8 milligrams) daily, starting at least one month before conception and continuing through the first 12 weeks of pregnancy. This amount is typically included in standard prenatal vitamins 1, 2, 3. Women with higher risk factors, such as those with a personal or family history of neural tube defects, those taking certain anti-seizure medications, or those with conditions like diabetes or obesity, may need higher doses of 4 milligrams daily as prescribed by their healthcare provider.
Key Considerations
- Folic acid is crucial during early pregnancy because it helps prevent serious birth defects of the baby's brain and spine called neural tube defects, including spina bifida and anencephaly 2.
- These structures form within the first 28 days after conception, often before a woman knows she's pregnant, which is why starting supplementation before pregnancy is important.
- Food sources of folate (the natural form of folic acid) include leafy green vegetables, citrus fruits, beans, and fortified grains, but supplements are still recommended to ensure adequate levels.
Evidence Summary
- The USPSTF recommends that all women planning pregnancy take a daily multivitamin containing folic acid at a dose of 0.4 to 0.8 mg beginning at least 1 month before conception and continuing through the first trimester, to reduce the risk for neural tube defects (grade A recommendation) 2.
- A meta-analysis of studies about pre- and periconceptional multivitamin use and congenital malformations also reported a protective effect of multivitamins containing folic acid against neural tube defects, with an odds ratio (OR) of 0.67 (95% CI, 0.58 to 0.77) in case–control studies and an OR of 0.52 (CI, 0.39 to 0.69) in RCTs and cohort studies 3.
From the FDA Drug Label
The usual therapeutic dosage in adults and children (regardless of age) is up to 1 mg daily... a daily maintenance level should be used, i.e., ... 0.8 mg for pregnant and lactating women The recommended daily intake of folic acid during pregnancy is 0.8 mg 4.
- The dose may need to be adjusted based on individual patient needs and medical conditions.
- Patients should be kept under close supervision to adjust the maintenance level as needed.
From the Research
Recommended Daily Intake of Folic Acid During Pregnancy
The recommended daily intake of folic acid during pregnancy varies based on the risk level of the woman.
- For women with a LOW RISK for a neural tube defect or other folic acid-sensitive congenital anomaly, a daily oral multivitamin supplement containing 0.4 mg folic acid is recommended for at least 2 to 3 months before conception, throughout the pregnancy, and for 4 to 6 weeks postpartum or as long as breast-feeding continues 5.
- For women with a MODERATE RISK, a daily oral supplementation with a multivitamin containing 1.0 mg folic acid is recommended, beginning at least 3 months before conception, and continued until 12 weeks' gestational age 5.
- For women with a HIGH RISK for a neural tube defect, a daily oral supplement with 4.0 mg folic acid is recommended for at least 3 months before conception and until 12 weeks' gestational age 5, 6, 7.
- The World Health Organization (WHO) and the majority of countries recommend a healthy diet plus a folic acid supplement of 400 µg/d from preconception until the end of the first trimester of pregnancy 8.
Key Considerations
- Women should be advised to maintain a healthy folate-rich diet in addition to taking folic acid supplements 5, 7.
- The timing of folic acid supplement usage is critical to preventing pregnancies affected by neural tube defects, as the neural tube closes by Day 28 post-conception 9.
- Women who have previously had an NTD-affected pregnancy should increase their intake of folic acid to 4000 microgram per day beginning at least 1 month before conception and continuing through the first trimester 6.