Casein & Gluten Free Dietary Supplement Scoop Inside Methylcobalamin is the most active form of vitamin B-12, and it is extremely important in folate chemistry and methylation processes. There are other forms of vitamin B-12; however, only methylcobalamin can be utilized in the central nervous system. Kirkman offers methylcobalamin in a concentrated powder that tastes good and dissolves quickly under the tongue or mixed in drinks. Cyanocobalamin is the most common form of vitamin B-12 and is the form used in most vitamin supplements. The reason for cyanocobalamin's presence in multivitamin supplements is its superb long-term stability and its relatively low cost. Cyanocobalamin is converted to methylcobalamin in the liver, but not in amounts that are considered significant. For this reason, many physicians are using very high doses of methylcobalamin. It is usually given subcutaneously, though some physicians are trying other routes of administration including oral administration.