Levomefolate is the calcium salt of 5-methyltetrahydrofolic acid , a biologically active form of folic acid that functions, in conjunction with Vitamin B12 , as a methyl-group donor involved in the conversion of homocysteine to methionine. The availability of methyl groups is essential for a variety of methylation reactions including the synthesis of DNA and proper neural tube closure. Levomefolate is included in formulations of certain oral contraceptives to ensure adequate folic acid levels in women of child-bearing age to reduce the risk of neural tube defects. The combination of levomefolate and oral contraceptives increases folic acid levels.
