Folate and its synthetic counterpart, folic acid, are forms of the water-soluble B vitamin, B9. This vitamin is a fundamental component in the creation of new cells and the synthesis of DNA and RNA. Because of its direct role in cell division and growth, B9 is particularly necessary during periods of rapid development, such as pregnancy. Understanding the distinction between folate and folic acid is key to ensuring adequate intake for maternal and fetal well-being.
Folate vs. Folic Acid Defining the Differences
Folate is the general term for the naturally occurring forms of Vitamin B9 found in various foods, such as leafy green vegetables, beans, peas, nuts, and citrus fruits. The name stems from the Latin word folium, meaning leaf. Natural folate is highly unstable and easily destroyed by cooking or storage, and only about 50% of the folate in food is absorbed.
Folic acid is the synthetic, fully oxidized form of Vitamin B9 used in dietary supplements and for fortifying foods like cereals, bread, and pasta. This synthetic version is chemically more stable than natural folate, retaining its potency for months or years. It is estimated to be approximately 85% bioavailable when taken with food. Chemically, folic acid is a monoglutamate and is fully oxidized, while food folates are typically reduced polyglutamates.
Essential Role in Preventing Neural Tube Defects
The focus on B9 intake during pregnancy is due to its influence on preventing Neural Tube Defects (NTDs), which are serious birth anomalies of the brain and spinal cord. NTDs include spina bifida and anencephaly. These defects occur very early in gestation, specifically during the first 28 days following conception, often before a person knows they are pregnant.
The prevention mechanism relates directly to B9’s function in DNA synthesis and cell proliferation, which accelerates as the embryonic neural tube forms and closes. Low B9 concentrations can impair this development, leading to an NTD. Adequate consumption of folic acid before conception and during the first trimester can reduce the occurrence of these defects by 50% or more. Because the neural tube closes so early, all individuals who could become pregnant should maintain sufficient B9 levels.
Metabolic Conversion and Genetic Factors
The body handles the two forms of B9 differently, requiring a multi-step metabolic process to convert them into the final usable compound. Both dietary folate and synthetic folic acid must ultimately be converted into the biologically active form, L-methylfolate (5-MTHF). This conversion allows the vitamin to participate in critical biochemical reactions, such as DNA methylation.
A specific enzyme, methylenetetrahydrofolate reductase (MTHFR), is responsible for converting folic acid into L-methylfolate. Variations (polymorphisms) in the MTHFR gene are common and can significantly reduce the enzyme’s efficiency, sometimes by as much as 70%. Individuals with these variants may struggle to process synthetic folic acid, potentially leading to a build-up of unmetabolized folic acid and insufficient active L-methylfolate. Therefore, some providers recommend supplementing with L-methylfolate, the already active form, to bypass the conversion step entirely.
Recommended Intake and Supplementation Guidelines
The standard recommendation for individuals capable of becoming pregnant is to consume 400 micrograms (mcg) of folic acid daily. This intake should begin at least one month prior to trying to conceive and continue through the first 12 weeks of pregnancy. This amount is often expressed in Dietary Folate Equivalents (DFEs) to account for folic acid’s higher bioavailability compared to food folate.
A significantly higher dosage is recommended for those at increased risk of an NTD-affected pregnancy, such as those with a previous NTD-affected pregnancy, a family history of NTDs, or certain medical conditions like diabetes. These individuals are advised to take 4,000 mcg (4 milligrams) of folic acid daily, starting one month before conception and continuing through the first three months of gestation.