What is the recommended dose of folic acid (Vitamin B9) for prenatal care?

From the Guidelines

The recommended dose of folic acid for prenatal care is 400 micrograms (0.4 mg) daily, starting at least one month before conception and continuing through the first 12 weeks of pregnancy, as supported by the most recent and highest quality study 1.

Key Points

• Folic acid supplementation is crucial for preventing neural tube defects, such as spina bifida and anencephaly, by supporting proper development of the baby's brain and spinal cord.
• The recommended dose of 400 micrograms (0.4 mg) daily is sufficient for most women, but those with higher risk factors, such as a personal or family history of neural tube defects, may require a higher dose of 4 mg daily as prescribed by their healthcare provider.
• Folic acid also supports rapid cell growth and division occurring during pregnancy and helps prevent certain types of anemia.
• The supplement is generally well-tolerated with minimal side effects.

Important Considerations

• Approximately 50% of pregnancies in the United States are unplanned, making universal prophylaxis with daily folic acid of 400 micrograms (0.4 mg) recommended for general reproductive-age women, in addition to a folate-rich diet.
• For high-risk women, a higher folic acid dose supplementation of 4,000 micrograms (4 mg) daily is recommended, commencing at least three months prior to conception and continuing until 12 weeks gestation.
• Continuation of 400 micrograms (0.4 mg) folic acid as a standard component of many prenatal vitamins is recommended throughout the rest of the pregnancy to meet the fetal growth and developmental needs.

From the FDA Drug Label

DOSAGE AND ADMINISTRATION ... and 0.8 mg for pregnant and lactating women, but never less than 0. 1 mg/day. The recommended dose of folic acid for prenatal care is 0.8 mg daily 2.

• The dose should not be less than 0.1 mg/day.
• It is essential to keep patients under close supervision and adjust the maintenance level as needed to prevent relapse.

From the Research

Folic Acid Dosage for Prenatal Care

• The recommended dose of folic acid for women who are planning or capable of pregnancy is 0.4 to 0.8 mg (400-800 µg) daily, as stated by the US Preventive Services Task Force 3.
• Women who could become pregnant should be advised to take a multivitamin containing 0.4 mg to 1.0 mg of folic acid daily 4.
• For women in intermediate- to high-risk categories for neural tube defects, high-dose folic acid (4.0 mg-5.0 mg daily) supplementation is recommended 4.
• It is essential to note that folic acid supplementation should be started before conception, ideally 5-6 months prior to pregnancy, to achieve optimal red-blood-cell folate levels 5.

Importance of Folic Acid Supplementation

• Folic acid deficiency in early pregnancy significantly increases the risk of neural tube defects in the developing fetus 6.
• Daily folic acid supplementation in the periconceptional period can prevent neural tube defects, which are among the most common major congenital anomalies 3.
• The benefits of folic acid supplementation include reduced lethal and severe morbidity birth defects, while the harms are minimal 4.

Monitoring and Guidance

• Women should be advised to maintain a healthy nutritional diet, as recommended in Canada's Food Guide to Healthy Eating, and to take a multivitamin containing folic acid daily 4.
• Healthcare providers should obtain a three-generation pedigree on the families of both the pregnant woman and the biological father to identify increased risk for congenital birth defects 4.
• Women who become pregnant should be advised of the availability of noninvasive screening tests and invasive diagnostic tests for congenital birth defects 4.