Vitamin B12, also known as cyanocobalamin, is a water-soluble vitamin. It is crucial in some of the metabolic reactions... moreVitamin B12, also known as cyanocobalamin, is a water-soluble vitamin. It is crucial in some of the metabolic reactions responsible for producing red blood cells and myelinating neurons all over the body. Vitamin B12 is naturally present in milk, shellfish, eggs and various fruits, and these sources provide all the cyanocobalamin needed by most people.Vitamin B12 is also available in formulated capsule forms,especially for people who require vitamin B12 supplementation.