What is the potential importance of taking folic acid?

Folic acid deficiency has been considered somewhat common in the U.S. It affects about 11% of healthy people, with a higher prevalence among African-Americans and Mexican-Americans.³⁷ Recently, however, the U.S. Food and Drug Administration (FDA) mandated that some grain products provide supplemental folic acid. This appears to be causing a reduction in the prevalence of folic acid deficiency in the general population.Nonetheless, some authorities believe the recent increases in folic acid content of the food supply are not enough to optimally prevent diseases such as heart disease and birth defects (see discussions below).

The requirement for folic acid doubles during pregnancy, and insufficient intake of folic acid has been linked to low birth weight and an increased incidence of neural tube defects in newborns. Supplementation with 400 mcg per day of folic acid prior to, and shortly after, conception is effective in preventing neural tube defects.