Used as a biochemical tool in cell culture media to support cell growth by aiding in the synthesis of nucleic acids and amino acids. Enhances the efficacy of certain chemotherapy drugs, particularly 5-fluorouracil, by stabilizing the binding to target enzymes in cancer treatment. Employed in research settings to study folate metabolism and one-carbon transfer reactions. Also utilized in some therapeutic formulations for reducing toxic side effects of antifolate drugs and in the management of certain types of anemia and neurological disorders linked to folate metabolism.