Vitamin B12 or cobalamin is a very complex chemical compound. Cobalamin is referring to the group of cobalt containing vitamer compound, this include cyanocobalamin, hydroxocobalamin, 5-deoxyadenosylcobalamin and methylcobalamin.
This vitamin required for the normal development of red blood cells, and a deficiency it causes acute pernicious anemia and a variety of other disorders. The exact requirement of Vitamin B-12 is yet unknown, since some B12 is synthesized by bacteria in the intestine. The organs of animals are excellent sources of Vitamin B12 and the muscles of warm-blooded animals and fish are good sources.
Vitamin B12 deficiency is commonly asymptomatic, but can also present as anemia characterized by enlarged blood corpuscle, so called megaloblastic anemia. However in serious case deficiency can potentially cause severe and irreversible damage to the nervous system.
Since body stores of vitamin B12 are adequate for up to five years, deficiency is generally the result of failure to absorb it. In older people, is also caused by inadequate intake of impaired absorption.
Megaloblastic anemia, Crohn's disease and other intestinal disorders are the most frequent causes of vitamin B12 deficiency.
Symptoms are attributable primarily to anemia, although glossitis, jaundice, and splenomegaly may be present. Vitamin B12 deficiency may cause decreased vibratory and positional sense, ataxia, paresthesias, confusion.
Apart from anemia due to vitamin B12 deficiency, the neurologic symptom of vitamin B12 deficiency include numbness and tingling of the arms and more commonly the legs, difficulty walking, memory loss, disorientation and dementia with or without mood changes.
Neurological or psychiatric symptoms occurs in about 40% of patents with vitamin B12 deficiency, in association with progressive damage to the spinal cord, peripheral nerves and cerebrum.
Deficiency of Vitamin B12