Cobalamin
Cobalamin or vitamin B12 is a chemical compound. Also known as cyanocobalamine. It is needed for nerve cells and red blood cells, and to make DNA.
It is an organometallic compound with a trivalent cobalt ion bound inside a corrin ring. Its chemical structure was determined by Dorothy Crowfoot Hodgkin.
Vitamin B12 is mostly absorbed in the terminal ileum. The production of intrinsic factor in the stomach is vital to absorption of this vitamin. Megaloblastic anemia can result from inadequate intake of vitamin B12, inadequate production of intrinsic factor (pernicious anemia), disorders of the terminal ileum resulting in malabsorption, or by competition for available B12 (such as fish tapeworms or bacteria present in the blind loop syndrome).
Neurological signs of B12 deficiency, which can occur without accompanying hematologic abnormalities, include demyelination and irreversible nerve cell death. Symptoms include numbness or tingling of the extremities and an ataxic gait.
In nature, B12 is solely produced by bacteria found in animals (including humans). It can sometimes be lacking in those following a vegetarian or vegan diet who do not make an effort to find foods naturally rich in B12 (such as spirulina or yeast extract or B12 enriched foodstuffs, which are sometimes soya based.
External link
- http://www.cc.nih.gov/ccc/supplements/vitb12.html
Referenced By
List of biomolecules | List of human blood components | Marmite | Vitamin | Vitamins | Where to buy marmite
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