Folic acid, or folate, is a B vitamin that must be derived from dietary sources or through supplementation.
Folate is necessary for a biochemical process in the body called methylation or one-carbon metabolism. This process does not function properly in a significant number of individuals who have a genetic polymorphism, and it can contribute to a host of different problems, including neural tube defects, depression, and reduced red blood cell production.
If a person is unable to properly convert folate, they may end up with a deficiency, even if they eat foods containing folate.