Absorption of water-soluble vitamins.
نویسنده
چکیده
The water-soluble vitamins vary widely in chemical structure and properties, so it is not surprising that the characteristics of absorption of individual members of the group also show differences. Water-soluble vitamins are absorbed mainly into the blood, some very freely (e.g. ascorbic acid), others (e.g. thiamine) only in limited amounts. Vitamin Biz has an apparently unique mode of absorption. On teleological grounds, it might be supposed that, since vitamins are essential to the body, special mechanisms would have been developed for each, to ensure the most effective absorption, but it is by no means certain that this is so. In general, there seems to be no means of regulating vitamin absorption. In deficiency, absorption does not become more effective (in some instances it may become less effective) and, in cases where the absorptive capacity is high in relation to the requirement, a great excess will be absorbed if ingested. Many vitamins of the B complex are synthesized by bacteria in the intestinal tract (Mickelsen, 1956; Donaldson, 1964). This source may meet the needs of ruminants and contribute to those of coprophagous animals, but it is very doubtful if it can be significantly utilized in man.
منابع مشابه
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ورودعنوان ژورنال:
- British medical bulletin
دوره 23 3 شماره
صفحات -
تاریخ انتشار 1967