What is the role of folic acid (Vitamin B9) in pregnancy and overall health?

From the Guidelines

Folic acid supplementation is crucial for preventing neural tube defects in pregnancy, and all women capable of pregnancy should take a daily multivitamin containing 0.4 to 0.8 mg of folic acid, starting at least one month before conception and continuing through the first trimester. The US Preventive Services Task Force recommends this dosage to reduce the risk of neural tube defects, which can develop in the first 28 days after conception, often before a woman knows she's pregnant 1.

Key Points

• Folic acid is essential for preventing neural tube defects like spina bifida and anencephaly
• Women planning or capable of pregnancy should take 0.4 to 0.8 mg of folic acid daily, starting at least one month before conception and continuing through the first trimester
• The recommended dosage may be higher (4 to 5 mg daily) for women with certain health risks, such as epilepsy, insulin-dependent diabetes mellitus, or a family history of neural tube defects 1
• Folic acid also supports red blood cell formation, DNA synthesis, and cell division, and helps prevent certain types of anemia and supports cardiovascular health

Benefits and Harms

• The benefits of folic acid supplementation in preventing neural tube defects are well-established, with a reduction in risk of nearly 75% 1
• The harms of folic acid supplementation are minimal, with no serious adverse effects reported at usual doses 1
• However, taking excessive amounts of folic acid (over 1,000 mcg daily) is unnecessary and could mask vitamin B12 deficiency symptoms

Clinical Considerations

• Healthcare providers should recommend folic acid supplements to all women capable of pregnancy, starting at least one month before conception and continuing through the first trimester
• Women with certain health risks or a history of neural tube defects may require higher doses of folic acid, and should consult with their healthcare provider to determine the best course of treatment 1

From the FDA Drug Label

Folic acid is usually indicated in the treatment of megaloblastic anemias of pregnancy. Folic acid requirements are markedly increased during pregnancy, and deficiency will result in fetal damage Studies in pregnant women have not shown that folic acid increases the risk of fetal abnormalities if administered during pregnancy. If the drug is used during pregnancy, the possibility of fetal harm appears remote. Folic acid requirements are markedly increased during pregnancy, and deficiency will result in fetal damage

The role of folic acid (Vitamin B9) in pregnancy is to prevent megaloblastic anemias and fetal damage due to deficiency. Folic acid is usually indicated in the treatment of megaloblastic anemias of pregnancy, and its requirements are markedly increased during pregnancy. According to the studies 2, folic acid does not increase the risk of fetal abnormalities if administered during pregnancy, and the possibility of fetal harm appears remote.

• Key points about folic acid in pregnancy:
  • Prevents megaloblastic anemias
  • Prevents fetal damage due to deficiency
  • Requirements are markedly increased during pregnancy
  • Does not increase the risk of fetal abnormalities if administered during pregnancy
  • Possibility of fetal harm appears remote 2

From the Research

Role of Folic Acid in Pregnancy

• Folic acid is crucial in preventing neural tube defects (NTDs) in pregnancy, with studies showing that periconceptional folic acid supplementation can prevent 50% or more of NTDs such as spina bifida and anencephaly 3.
• The American Academy of Pediatrics recommends that all women capable of becoming pregnant consume 400 microgram of folic acid daily to prevent NTDs 3.
• Folic acid supplementation is critically important for childbearing mothers before conception and in the first trimester pregnancy, with decreased blood folic acid levels inhibiting DNA replication, repair, RNA synthesis, histone and DNA methylation, methionine production, and homocysteine remethylation reactions that cause NTDs in pregnancy 4.

Importance of Timing and Duration of Folic Acid Supplementation

• The timing and duration of folic acid supplementation are important in achieving optimal red blood cell (RBC) folate levels in early pregnancy, which are necessary for the prevention of NTDs 5.
• Women who start folic acid supplementation 4-8 weeks before their last menstrual period (LMP) are more likely to achieve optimal RBC folate levels compared to those who start 4-8 weeks after their LMP 5.
• Folic acid supplementation should be started before conception, as the first trimester is a critical period for neural tube closure 4, 5.

Folic Acid Supplementation in Preventing Other Birth Defects

• There is increasing evidence that folic acid supplementation may reduce the incidence of oral facial clefting, in addition to preventing NTDs 6.
• Further research is needed to fully understand the role of folic acid in preventing other birth defects, including oral facial clefting 6.

Current Practices and Challenges in Folic Acid Supplementation

• Despite the importance of folic acid supplementation, many women do not consume the recommended amount of folic acid, with fewer than 1 in 3 women consuming the amount recommended by the US Public Health Service 3.
• The realization of the Primary Prevention Program of Neural Tube Defects leaves much to be desired, with over half of women not supplementing folic acid before conception, and the supply in pregnancy being initiated too late to meet the assumptions of the prevention program 7.