Circulating Unmetabolized Folic Acid: Relationship to Folate Status and Effect of Supplementation

Figure 1

Structure of folic acid [1]. The three parts of the parent structure include 2-amino-4-oxo-pteridine, p-aminobenzoic acid, and glutamic acid. Substitutions (one-carbon groups) occur at the N5 and/or N10 positions.