Vitamin B12 - Do You Know Everything?

BACKGROUND The term Vitamin B12 is used as a generic descriptor for the cobalamins; cobalt containing compound possessing the corrin ring having the biological activity of vitamin. The active coenzyme forms of vitamin B12 are methylcobalamin and deoxyadenosylcobalamin. Dietary sources of vitamin B12 are of animal origin and include meat, eggs, milk, dairy products, fish and poultry. Vitamin B12 is absent in plant foods and humans obtain small amount of vitamin B12 from their intestinal flora. Vitamin B12 plays a crucial role in DNA synthesis, nucleoprotein, erythropoiesis, myelin synthesis, normal growth and cell reproduction and one carbon metabolism. Vitamin B12 deficiency may arise due to decreased dietary intake. Vitamin B12 helps in isomerization of methylmalonyl-CoA to succinyl-CoA by methylmalonyl-CoA mutase and also helps in conversion of homocysteine to methionine by methionine synthase. Dietary deficiency is seen in strict vegetarians, since vitamin found only in foods of animal origin or in microorganism. Deficiency of Vitamin B12 causes pernicious anaemia, megaloblastic anaemia, methylmalonic aciduria, Neuropathy and folate trap. The present review concludes that vitamin B12 deficiency affects a person's mental and physical health and it can cause severe, irreversible neurologic damage, disorientation, nerve damage, insomnia and many other diseases as mentioned in article. Adults should take 2.4 mcg of vitamin B12, deficiency is mainly seen commonly in Vegetarian they have to add vegan sources of vitamin B12 to their diet which include fortified cereals, bread, nutritional yeast and plant milks. Early identification of vitamin B12 status should be preliminary screening step to reverse the damage caused by vitamin B12 deficiency which will helps in prevention of diseases.