Vitamin B12 is an essential vitamin. It is necessary for maintaining the integrity of the nervous system and in the production of energy. The metabolism of vitamin B12 and folate are closely linked, as vitamin B12 functions as a co-factor in folate formation in the body. The primary form of vitamin B12 used in supplements is cyanocobalamin. This form must be converted by the body to the active form of B12, known as methylcobalamin. Because B12 Infusion utilizes methylcobalamin as the source of vitamin B12, no conversion is necessary.