What is the Importance of vitamin B₁₂

Vitamin B₁₂ deficiency is manifest by the  symptoms of pernicious anaemia (Addison-Biermer's disease). An irreversible atrophy of the gastric mucose is primarily responsible for pernicious anaemia, causing loss of the intrinsic factor, which is predominantly produced in stomach. Vitamin B₁₂ from the ingested food is bound by intrinsic factor that reaches intestine for absorption. In addition, vitamin B₁₂ acts as a mediator in the formation of labile methyl groups for the synthesis of methionine. This explains its lipotropic and protein saving effect. In various animal species, increased growth may be produced by administration of vitamin B₁₂. Also, in children, the growth promoting activity of vitamin B₁₂  has been observed.