What Is Folic Acid and Why Is It Essential?
Folic acidâalso known as vitamin B9âis an essential nutrient needed for DNA replication, amino acid metabolism, and red blood cell (RBC) production. During pregnancy, the bodyâs demand for folic acid skyrockets due to the rapid growth and development of the fetus, particularly the formation of the brain, spine, and red blood cells.
Without sufficient folic acid, both mother and baby can face serious health issues, including anemia, neural tube defects (NTDs), and other congenital abnormalities.
Folic Acid, Folate, and L-Methylfolate: Whatâs the Difference?
- Folate: The natural form found in foods like leafy greens, legumes, liver, and citrus.
- Folic acid: A synthetic form added to supplements and fortified foods.
- L-methylfolate: The biologically active form that the body uses for metabolic functions.
Both folate and folic acid must be converted into L-methylfolate to become active. This conversion is dependent on an enzyme called MTHFR (methylenetetrahydrofolate reductase)âbut up to 60% of the population has genetic variations that make this process less efficient.
Because of this, newer recommendations are beginning to favor L-methylfolate supplements, especially for individuals with known MTHFR mutations.
Folic Acidâs Critical Role in Pregnancy
đ§ Prevents Neural Tube Defects (NTDs)
Neural tube defects like spina bifida and anencephaly occur early in pregnancy, often before a woman knows she is pregnant. Periconceptional folic acid supplementation (400â1000 mcg daily) can reduce the risk of these conditions by 70% or more.
This has led many countries, including the U.S. and Canada, to fortify grain products with folic acid, dramatically lowering NTD rates.
â¤ď¸ Supports Red Blood Cell Production
Pregnancy increases blood volume, including the number of red blood cells. But if thereâs a folic acid deficiency, this process is impairedâleading to anemia, fatigue, and poor oxygen delivery to both mother and baby.
A clinical trial comparing prenatal supplements found that women who received 1.13 mg of L-methylfolate plus vitamin B12 had higher hemoglobin levels at delivery compared to those who received folic acid alone.
đ May Reduce Preterm Birth Risk
Emerging research shows folic acid may lower the risk of preterm birthâparticularly when taken for more than one year before conception. One large U.S. study found that women who supplemented early had up to a 78% reduced risk of delivering between 20â28 weeks gestation.
đą Helps Prevent Other Birth Defects
Folic acid may also reduce the risk of:
- Congenital heart defects
- Cleft lip and palate
- Placental complications like preeclampsia and placental abruption
These benefits are believed to stem from folic acidâs role in regulating homocysteine metabolism and trophoblast function, both critical in early fetal development.
â ď¸ What About Too Much Folic Acid?
High levels of synthetic folic acid may:
- Mask vitamin B12 deficiency
- Leave unmetabolized folic acid in the bloodstream
- Potentially affect mood and cognitive function (especially in older adults)
As a result, some experts now recommend L-methylfolate supplementation instead, especially for those at risk of impaired folate metabolism.
Conclusion: A Tiny Vitamin with a Huge Impact
Folic acid is a cornerstone of prenatal careâcritical not only for preventing birth defects but also for supporting red blood cell production and reducing pregnancy complications. Whether taken as folic acid or the more active L-methylfolate, this vitamin plays a vital role in a healthy pregnancy and baby.
If youâre pregnant, trying to conceive, or planning ahead, talk to your healthcare provider about the best form and dosage for your needs.
Source:
Greenberg JA, Bell SJ, Guan Y, Yu Y. Folic Acid Supplementation and Pregnancy: More Than Just Neural Tube Defect Prevention. Reviews in Obstetrics & Gynecology. 2011;4(2):52-59. [DOI: 10.3909/riog0157]