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vitamin B12A water-soluble vitamin of animal origin required for DNA synthesis. It is a glycoprotein produced and secreted by the gastric parietal cells, and is absorbed from the GI tract bound to intrinsic factor; the body stores up to one years’ worth of vitamin B12 in the liver, kidneys and heart. Rapid cell turnover (e.g., growth spurts in children, malignancy) require increased amounts of vitamin B12. Vegans, who ingest no protein of animal origin, are at risk for vitamin B12 deficiency.
Chronic myeloid leukaemia, chronic obstructive pulmonary disease, congestive heart failure, liver disease, obesity, polycythemia vera, renal failure.
Atrophic gastritis, drugs (antibiotics, anticonvulsants, antimalarials, antituberculous agents, chemotherapy, contraceptives, diuretics, oral hypoglycemics, sedatives), inflammatory bowel disease (e.g., Crohn’s disease, ulcerative colitis), intrinsic factor deficiency (causing megaloblastic anaemia), malabsorption, malnutrition, parasites (e.g., Diphyllobotrium latum), veganism.
vitamin B12Cyanocobalamin, extrinsic factor, methylcobalamin Clinical nutrition A water-soluble vitamin of animal origin, required for DNA synthesis; absorbed from the GI tract bound to intrinsic factor; it is a glycoprotein produced and secreted by the gastic parietal cells; the body stores up to one yr's worth of vitamin B12 in the liver, kidneys, heart; rapid cell turnover–eg, growth spurts in children, CA require ↑ amounts of vitamin B12. ↑CML, COPD, CHF, liver disease, obesity, polycythemia vera, renal failure. ↓Atrophic gastritis, drugs–antibiotics, anticonvulsants, antimalarials, antituberculous agents, chemotherapy, contraceptives, diuretics, oral hypoglycemics, sedatives; IBD–eg, Crohn's disease, ulcerative colitis; intrinsic factor deficiency–causing megaloblastic anemia, malabsorption, malnutrition, parasites–eg, Diphyllobotrium latum, veganism. Note: A strict vegetarian diet's victim ingests no proteins of animal origin, including meat, fish and dairy products; all vegans are at risk for vitamin B12 deficiency; in addition, vegan adolescents may not meet energy requirements during the growth spurt and may become deficient in vitamin B6 and riboflavin; the high-fiber diet may chelate calcium, zinc and iron, and ↓ absorption of essential cations and trace minerals See Intrinsic factor, Pareve, Vegan, Vegetariansim; Cf Lacto-ovo vegetarian.
vitamin B12one of the B-COMPLEX of water-soluble vitamins, containing cobalt and required for red blood cell formation. A deficiency of B12 can lead to pernicious anaemia especially amongst old people. The vitamin is synthesized by bacteria in the gut rather than being obtained from the diet, and is required in very tiny amounts. The richest food source is raw liver.
Patient discussion about vitamin B12
Q. Can a food rich in vitamin B12 will help for his depression or vitamin B12 pills are always required? Hi all…..having one question related to my friends depression and its relation to vitamin B12, as a medicine given to him by his Doctor. Can a food rich in vitamin B12 will help for his depression or vitamin B12 pills are always required?