Vitamin B12 and folate are vitamins required for normal haematopoiesis and neurologic function. They are often considered together, although folate deficiency has become exceedingly rare in individuals who are living in developed countries and consuming a normal diet.
Vitamin B12 is also called cobalamin (Cbl). The endogenous forms include cobalamin and holotranscobalamin, which represent the active fraction of plasma cobalamin. The supplemental forms used to treat vitamin B12 deficiency include cyanocobalamin, which contains a cyanide (CN) atom introduced during chemical synthesis, and hydroxocobalamin.
Diagnosis of B12 and Folate Deficiency