How does vitamin B12 work? Vitamin B12 is essential for closing the neural tube. It is crucial since it functions as a cofactor in two important enzymes; one functions transferring a methyl group from 5-methyltetrahydrofolate (5-THF) to homocysteine, regenerating tetrahydrofolate (THF, the active form of folic acid) and methionine. A lack of B12 creates a […]