5-MTHF is the most biologically active form of the B-vitamin folic acid. 5MTHF works in concert with vitamin B12 (methylcobalamin) in the conversion of homocysteine to methionine, which provides methyl groups for numerous other biochemical reactions in the body. Because of this, folate supplementation supports cardiovascular health, nervous system function, normal cellular proliferation, and gingival health. Folate supplementation during pregnancy has been shown to reduce the risk of neural tube defects.