共查询到20条相似文献,搜索用时 15 毫秒
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A Doscherholmen J McMahon D Ripley 《Proceedings of the Society for Experimental Biology and Medicine. Society for Experimental Biology and Medicine (New York, N.Y.)》1975,149(4):987-990
The assimilation of 57Co B12 from in vivo labeled eggs was much inferior to that of a comparable amount of crystalline 57Co B12. Furthermore, the absorption varied with the form in which the eggs were served. Judged by the urinary excretion test and the plasma absorption of radioactivity the average absorption from boiled and fried eggs was more than twice that from scrambled whole eggs, but less than half that absorbed from crystalline 57Co B12. 相似文献
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A third vitamin B12 binding protein present in normal serum has been shown to participate in transport of labelled vitamin B12 absorbed from the gut. All three vitamin B12 binding proteins in serum were labelled at the same time after oral administration of vitamin B12, implying that “free” vitamin B12 reached the portal blood from the gut mucosa. 相似文献
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240 зтаммов актиномицетов, выделенных из ризосферы различных растений и из различных почв, исследовались на наличие витамина В12 путем культивирования в жидкой питательной среде. 73% из исследованных штаммов обладают способностью образовывать витамин В12, в количестван порядка 0,0025–1,6 μ/мл. Количество продуцентов зависит от растительного покрова. Серия Helvolus включает наибольшее количество продуцентов (93,3%). 相似文献
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Vitamin B12 sources and bioavailability 总被引:2,自引:0,他引:2
Watanabe F 《Experimental biology and medicine (Maywood, N.J.)》2007,232(10):1266-1274
The usual dietary sources of vitamin B(12) are animal foods, meat, milk, egg, fish, and shellfish. As the intrinsic factor-mediated intestinal absorption system is estimated to be saturated at about 1.5-2.0 microg per meal under physiologic conditions, vitamin B(12) bioavailability significantly decreases with increasing intake of vitamin B(12) per meal. The bioavailability of vitamin B(12) in healthy humans from fish meat, sheep meat, and chicken meat averaged 42%, 56%-89%, and 61%-66%, respectively. Vitamin B(12) in eggs seems to be poorly absorbed (< 9%) relative to other animal food products. In the Dietary Reference Intakes in the United States and Japan, it is assumed that 50% of dietary vitamin B(12) is absorbed by healthy adults with normal gastro-intestinal function. Some plant foods, dried green and purple lavers (nori) contain substantial amounts of vitamin B(12), although other edible algae contained none or only traces of vitamin B(12). Most of the edible blue-green algae (cyanobacteria) used for human supplements predominantly contain pseudovitamin B(12), which is inactive in humans. The edible cyanobacteria are not suitable for use as vitamin B(12) sources, especially in vegans. Fortified breakfast cereals are a particularly valuable source of vitamin B(12) for vegans and elderly people. Production of some vitamin B(12)-enriched vegetables is also being devised. 相似文献
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