ADM Specialty Ingredients (Europe) B.V., Stationsstraat 76, Koog aan de Zaan, The Netherlands.
J Sci Food Agric. 2010 Aug 15;90(10):1571-7. doi: 10.1002/jsfa.3994.
Bio-availability of different alpha-tocopherol forms in livestock animals is measured by the increase in plasma or tissue concentrations of alpha-tocopherol after oral administration. It is generally accepted that RRR-alpha-tocopheryl acetate (natural source vitamin E derived from vegetable oil) has a higher bio-availability compared to all-rac-alpha-tocopheryl acetate (synthetic vitamin E, i.e. alpha-tocopherol produced by chemical synthesis). However, different bio-availability ratios have been reported in the literature. The major reason for conflicting results in literature studies was the inability to separate the proportion of alpha-tocopherol originating from test materials, from the proportion of alpha-tocopherol originating from basal dietary ingredients and pre-feeding. This causes significant variability. For bio-availability determination, a baseline or control treatment is essential. The estimation of bio-availability without correction for basal vitamin E status will lead to incorrect interpretation of the results. When using proper methodologies, it is possible to correct for the impact of alpha-tocopherol intake from basal ingredients and alpha-tocopherol originating from pre-feeding, therefore yielding results reflecting the true relative bio-availability of different alpha-tocopherol substances. When reviewing literature data a critical evaluation of the method used in determination of relative bio-availability is recommended.
不同形式的α-生育酚在牲畜中的生物利用度是通过口服后血浆或组织中α-生育酚浓度的增加来衡量的。一般认为，RRR-α-生育酚醋酸酯（天然来源的维生素 E，来源于植物油）比全反式-α-生育酚醋酸酯（合成维生素 E，即通过化学合成生产的α-生育酚）具有更高的生物利用度。然而，文献中报道的生物利用度比值不同。文献研究中结果不一致的主要原因是无法将来自测试材料的α-生育酚比例与来自基础日粮成分和预饲的α-生育酚比例分开。这会导致很大的变异性。对于生物利用度的测定，基线或对照处理是必不可少的。如果不纠正基础维生素 E 状态，对生物利用度的估计将导致对结果的不正确解释。当使用适当的方法时，可以纠正基础成分和预饲中α-生育酚摄入的影响，从而得出反映不同α-生育酚物质真实相对生物利用度的结果。在审查文献数据时，建议对相对生物利用度测定中使用的方法进行批判性评估。
