Folic acid, a water-soluble B-complex vitamin included in supplements and fortified foods, is used in the human body for synthesis of nucleic acids and amino acids. Natural food sources of folate include dark green leafy vegetables, citrus fruits and juices, legumes and liver.
Folic acid is well-tolerated in amounts found in fortified foods and dietary supplements. The U.S. Food and Drug Administration (FDA) has established a Reference Daily Intake (RDI) of 400 μg folate for adults and children 4 or more years of age (21CFR101.9). RDIs are a set of dietary references for essential vitamins and minerals that are considered amounts sufficient to meet the daily requirements of healthy individuals. RDIs serve as the basis for calculating the percent daily value (%DV) amounts found on dietary supplement and food labels.