Vitamin E bioavailability in humans
Vitamin E bioavailability in humans
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DOI：
10.1016/j.jplph.2005.04.012
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发表时间：
2005-07-01
影响因子：
4.3
通讯作者：
Lodge, JK
中科院分区：
文献类型：
--
作者：
Lodge, JK
重要的是要了解影响维生素E生物利用度的因素，特别是在冠心病风险增加的人群中，如吸烟者。还需要澄清天然和合成维生素E的生物利用度，这是目前存在一些争议的问题。以前使用竞争性摄取方法的研究发现，天然：合成维生素E的生物利用度比接近2：1，与公认的生物效能比1.36：1不同。我们使用非竞争性摄取方法比较了吸烟者和非吸烟者中氘代天然（RRR）和合成（全外消旋）α-生育酚乙酸酯的血浆生物代谢动力学。该研究包括两次400 mg/d（RRR-alpha-生育酚或所有rac-alpha-生育酚乙酸酯）的4周治疗，其间有12周的洗脱期。在每次治疗之前和之后，受试者经历了48小时的生物动力学方案，其中使用150 mg RRR或所有外消旋形式的氘代α-生育酚乙酸酯。吸烟者在给予RRR后的氘代α-生育酚AUC低于非吸烟者，但在给予所有rac后无差异。在非吸烟者和吸烟者中，RR：AUC和C-max的所有rac的比率为1.3：1，吸烟者为0.9：1。补充维生素E后，两组的氘代生育酚AUC均降低。这些数据表明，非吸烟者和吸烟者在处理维生素E方面存在差异，天然和合成维生素E的相对生物利用度接近目前公认的生物效价比1.36：1，补充后血浆吸收新吸收的维生素E的能力降低。(c)2005年Elsevier GmbH。All rights reserved.
It is important to understand factors that can influence vitamin E bioavailabitity, particularly in populations with increased risk of coronary heart disease such as cigarette smokers. There is also a need to clarify the bioavailability of natural and synthetic vitamin E, which is currently a subject of some controversy. Previous studies using a competitive uptake approach have found bioavailability ratios of natural:synthetic vitamin E close to 2:1, differing from the accepted biopotency ratio of 1.36:1. We used a non-competitive uptake approach to compare the plasma biokinetics of deuterated natural (RRR) and synthetic (all rac) alpha-tocopheryl acetate in smokers and non-smokers. The study was comprised of two 4-week treatments with 400mg/d (either RRR-alpha-tocopheryl or all rac-alpha-tocopheryl acetates), with a 12-week washout period between. Prior to and after each treatment subjects underwent a 48 h biokinetic protocol with 150 mg deuterated alpha-tocopheryl acetate in either the RRR or all rac form. Smokers had a lower deuterated alpha-tocopherol AUC than did non-smokers following administration of RRR, but there was no difference following administration of all rac. The ratio RRR:all rac from AUCs and C-max was 1.3:1 in non-smokers and 0.9:1 in smokers. Following vitamin E supplementation, deuterated tocopherol AUCs were tower in both groups. These data suggest that non-smokers and smokers differ in their handling of vitamin E, that the relative bioavailabitity of natural and synthetic vitamin E is close to the currently accepted biopotency ratio of 1.36:1, and that following supplementation the ability of the plasma to take up newly absorbed vitamin E is decreased. (c) 2005 Elsevier GmbH. All rights reserved.