Folic acid is a type of B vitamin. It is the synthetic form of folate that is found in supplements and added to fortified foods. Folate is a generic term for both naturally occurring folate found in foods and folic acid. Folic acid is not stored in the body and you need a continuous supply of the vitamin in the foods you eat. Folate occurs naturally in dark green leafy vegetables, dried beans and peas (legumes), citrus fruits and juices.
One of the most important uses of folate in the body, is as a precursor of methyl groups. Methyl groups are needed for many biochemical reactions in the body, and also for turning genes on and off. (Epigenetics)
The MTHFR gene encodes an enzyme (Methylenetetrahydrofolate reductase) that is critical in the metabolism of folate. People who are deficient in this enzyme are unable to convert folic acid to its active forms in the body, and as a result, have a build up of toxic by-products such as Homocysteine, which has been associated with heart disease and dementia.
A Heterozygous mutation decreases the activity of this enzyme by 35% while a Homozygous mutation decreases its activity by 70% percent. However, most people with a mutation remain unaffected and do not experience symptoms.
Related to:
folate, folic acid