Absorption and Distribution of Vitamin E in the Tissues

Abstract

Publisher Summary The mechanism of the absorption of vitamin E is undoubtedly very similar to that of the other fat soluble vitamins, but compared to vitamin A, for example, its efficiency appears to be much lower. The specific site of absorption is not too well established, but it is probably linked with fat and oil absorption and is facilitated by bile. It has also been noted that the difference in the efficiency of absorption of an oil solution and an aqueous emulsion of vitamin E is not a great as the difference encountered with vitamin A. It is apparent from the work of several investigators that a high percentage of a test dose of tocopherol is excreted in the feces. The data from balance studies and the considerable data collected on blood and liver levels of tocopherol, however, strongly indicate that the absorption of vitamin E is incomplete. With the establishment of the quantitative relationship between tocopherol intake and liver storage together with the availability of precise methods of measurement of the tocopherol in the liver, a method for the bioassay of tocopherols based on liver storage was quick to develop. Although there is agreement concerning a linear relationship between tocopherol intake and liver tocopherol storage, there is some controversy over the relationship between tocopherol intake and plasma tocopherol.