An estimation of selenium requirements for New Zealanders.
An estimation of selenium requirements for New Zealanders.
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DOI：
10.1093/ajcn/70.5.896
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发表时间：
1999-11
期刊：
影响因子：
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通讯作者：
A. Duffield;C. Thomson;K. Hill;Sheila M. Williams
中科院分区：
文献类型：
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作者：
A. Duffield;C. Thomson;K. Hill;Sheila M. Williams
背景 根据一项针对中国男性的研究数据，美国当前的硒饮食建议是基于血浆谷胱甘肽过氧化物酶 (GSHPx) 活性的最大化。目的 研究不同剂量的硒补充对新西兰成年人血液中 GSHPx 活性的影响，以计算新西兰人的硒需求量。还研究了对血浆硒蛋白 P 和甲状腺激素的影响。设计 52 名血硒浓度较低的成年人每天摄入安慰剂或 10、20、30 或 40 微克硒（L-硒代蛋氨酸），持续 20 周。结果 根据统计分析确定，所有补充组的血浆和全血 GSHPx 活性均有所增加，但仅在接受 40 微克 Se 的组中达到稳定水平。在所有补充剂摄入量中，硒蛋白 P 的增加均大于硒和 GSHPx 的增加。补充组中甲状腺素浓度下降，但仅 10 微克组和所有补充组的下降幅度与对照组显着不同。结论 90 微克 Se/d 的估计需求上限被计算为血浆 GSHPx 活性最大化所需的摄入量，用于推导美国推荐的每日摄入量。我们的较低估计需求量为 39 微克 Se/d，是达到最大 GSHPx 活性三分之二所需的摄入量，用于计算世界卫生组织的规范要求。对于新西兰来说，较低的估计是一个现实的目标，但较高的估计只有通过定期添加高硒食品才能实现。
BACKGROUND Current US dietary recommendations for selenium are based on maximization of plasma glutathione peroxidase (GSHPx) activity according to data from one study of Chinese men. OBJECTIVE The effect of various amounts of supplemental selenium on GSHPx activities in blood of New Zealand adults was investigated to calculate a selenium requirement for New Zealanders. The effect on plasma selenoprotein P and thyroid hormones was also investigated. DESIGN Fifty-two adults with low blood selenium concentrations ingested a placebo or 10, 20, 30, or 40 microgram Se as L-selenomethionine daily for 20 wk. RESULTS Plasma and whole-blood GSHPx activities increased in all supplemented groups but reached a plateau only in the group receiving 40 microgram Se, as determined by statistical analysis. Increases in selenoprotein P were greater than those for selenium and GSHPx at all supplement intakes. Thyroxine concentrations decreased in supplemented groups but the decrease was significantly different from that in the control group only for the 10-microgram group and for all supplemented groups combined. CONCLUSIONS An upper estimated requirement of 90 microgram Se/d was calculated as the intake necessary for maximization of plasma GSHPx activity, as used in the derivation of the US recommended daily allowance. Our lower estimated requirement of 39 microgram Se/d was the intake necessary to reach two-thirds of maximal GSHPx activity, as was used in calculating the World Health Organization normative requirement. The lower estimate is a realistic goal for New Zealand but the upper estimate could be achieved only with regular inclusion of high-selenium foods.