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8 Answers
- 1 decade agoFavorite Answer
Vitamin B12 is a member of the vitamin B complex. It contains cobalt, and so is also known as cobalamin. It is exclusively synthesised by bacteria and is found primarily in meat, eggs and dairy products. There has been considerable research into proposed plant sources of vitamin B12. Fermented soya products, seaweeds, and algae such as spirulina have all been suggested as containing significant B12.
Vitamin B12 is necessary for the synthesis of red blood cells, the maintenance of the nervous system, and growth and development in children. Deficiency can cause anaemia. Vitamin B12 neuropathy, involving the degeneration of nerve fibres and irreversible neurological damage, can also occur.
Vitamin B12's primary functions are in the formation of red blood cells and the maintenence of a healthy nervous system. B12 is necessary for the rapid synthesis of DNA during cell division. This is especially important in tissues where cells are dividing rapidly, particularly the bone marrow tissues responsible for red blood cell formation.
B12 plays a vital role in the metabolism of fatty acids essential for the maintainence of myelin. Prolonged B12 deficiency can lead to nerve degeneration and irreversible neurological damage.
When deficiency occurs, it is more commonly linked to a failure to effectively absorb B12 from the intestine rather than a dietary deficiency. Absorption of B12 requires the secretion from the cells lining the stomach of a glycoprotein, known as intrinsic factor. The B12-intrinsic factor complex is then absorbed in the ileum (part of the small intestine) in the presence of calcium. Certain people are unable to produce intrinsic factor and the subsequent pernicious anaemia is treated with injections of B12.
Vitamin B12 can be stored in small amounts by the body. Total body store is 2-5mg in adults. Around 80% of this is stored in the liver.
Vitamin B12 is excreted in the bile and is effectively reabsorbed. This is known as enterohepatic circulation. The amount of B12 excreted in the bile can vary from 1 to 10ug (micrograms) a day. People on diets low in B12, including vegans and some vegetarians, may be obtaining more B12 from reabsorption than from dietary sources. Reabsorption is the reason it can take over 20 years for deficiency disease to develop in people changing to diets absent in B12. In comparison, if B12 deficiency is due to a failure in absorption it can take only 3 years for deficiency disease to occur.
- 1 decade ago
Vitamin B12 helps maintain healthy nerve cells and red blood cells [1-4]. It is also needed to help make DNA, the genetic material in all cells. Vitamin B12 is also called cobalamin because it contains the metal cobalt [1-4].
Vitamin B12 is bound to the protein in food. Hydrochloric acid in the stomach releases vitamin B12 from proteins in foods during digestion. Once released, vitamin B12 combines with a substance called intrinsic factor (IF). This complex can then be absorbed by the intestinal tract.
- 1 decade ago
It is a vitamin that increase your metabolism and gives you energy. It doesn't make your heart race at all. It is a really good vitamin. They also make B12 shots you can get from your physician.
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- Anonymous1 decade ago
well, ive been trying to figure that out, if this helps at all I am a vegan and I was told when I first became vegan that i needed to get a vitamin w/ B12 because I woulldn't be getting enough of it without meat and dairy.