Serum Unmetabolized Folic Acid: The Straw That Broke Dihydrofolate Reductase's Back?

The article discusses research done on serum unmetabolized folic acid (UMFA). It references the study "Unmetabolized Folic Acid Is Detected in Nearly All Serum Samples From US Children, Adolescents, and Adults" by C. M. Pfeiffer and colleagues published within the issue. Topics discussed include the effects of vitamin use and fasting conditions on folate forms, the effect of vitamin usage on UMFA, and predictors of the presence of UMFA in serum.