B12 Folate is the most biologically active form of the water-soluble B vitamin, folate. It is the preferred form of folate supplementation due to an array of conditions that can limit conversion or absorption of folic acid. Data indicate that supplementing with 5-MTHF increases plasma folate more effectively than folic acid. MecobalActive™, which is found in the B12 Folate formula, is a highly pure form of methylcobalamin that does not use any harmful solvents during manufacture.*