Cyanocobalamin or vitamin-B12 is an essential vitamin of the B-complex. It is required by animals that use it as a cofactor in DNA synthesis and in fatty acid and amino acid metabolism. It is important for the normal functioning of the nervous system through its role in the synthesis of myelin and in the circulatory system during the maturation of red blood cells in the bone marrow.
As a drug, it is given for vitamin B12 deficiency, also called pernicious anemia. It can be administered intravenously, perorally or as a nasal spray. In addition, it can be administered in highly concentrated form as an antidote in the event of cyanide poisoning.