Methyl Folate ((6S)-5-methyltetrahydrofolic acid or (6S)-5-MTHF) is the most biologically active form of folic acid. Quatrefolic® is the 4th generation development in folate delivery. With certain inherited errors in metabolism and physiologic stresses; the transformation of folic acid into the active form of folate is inadequate.* Unlike folic acid; 5-MTHF can cross the blood-brain barrier.* HEALTH CLAIM: Healthful diets with adequate folic acid may reduce a woman’s risk of having a child with certain brain or spinal cord defects. Keep out of the reach of children.