Use of a short-term isotope-dilution method for determining the vitamin A status of children
Use of a short-term isotope-dilution method for determining the vitamin A status of children
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DOI：
10.1093/ajcn/76.2.413
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发表时间：
2002-08-01
影响因子：
7.1
通讯作者：
Russell, RM
中科院分区：
文献类型：
--
作者：
Tang, GW;Qin, J;Russell, RM
背景：给人体服用一定剂量的标记维生素A以估计体内维生素A的储存量后，通常在11~26d的假平衡时间抽血。目的：目的：确定是否可以使用更短的样本采集间隔(6h或3d)，在野外环境下更接近实际情况。设计：对维生素A状态从边缘到正常的中国学龄儿童(10-11岁；n=58)口服标记维生素A后，进行6h或3d的浓缩与21d的浓缩的相关性。然后推导出一个预测方程，并将其应用于从一组单独的儿童获得的数据，以验证计算的第21天的丰度(通过使用较早的时间点获得的数据来预测21天的丰度)反映了第21天的直接测量丰度。结果：由于发现3-d的同位素丰度与21 d的丰度有很好的相关性，因此导出了一个预测方程，利用3D数据预测伪平衡时(即21 d时)的同位素丰度。当将三维预测方程应用于单独的一组中国儿童时，计算的21维数据(由三维数据和预测方程确定)与直接测量的21维数据相匹配。由计算的或直接测量的21天浓缩数据确定的维生素A体内储量也显示出一致性。结论：3d(而不是6小时)的百分比浓缩可以用来评估人体维生素A的体内储量。
Background: After a dose of labeled vitamin A is given to humans for estimating body stores of vitamin A, blood is customarily drawn at pseudo-equilibration times ranging from 11 to 26 d.Objective: The objective was to determine whether a shorter sample collection interval (6 h or 3 d), which would be more realistic in field settings, can be used.Design: Correlations of enrichment at 6 h or 3 d with enrichment at 21 d were made after an oral dose of deuterium-labeled vitamin A was given to Chinese schoolchildren (aged 10-11 y; n = 58) with marginal-to-normal vitamin A status. A predictive equation was then derived and applied to data obtained from a separate group of children to verify that the calculated enrichment at 21 d (determined by using data obtained at an earlier time point to predict 21-d enrichment) reflected directly measured enrichment at 21 d.Results: Because 3-d isotope enrichment was found to correlate well with 21-d enrichment, a predictive equation was derived whereby 3-d data were used to predict isotope enrichment at pseudo-equilibration (ie, at 21 d). When the 3-d predictive equation was applied to a separate group of Chinese children, the calculated 21-d data (determined by using the 3-d data and the predictive equation) matched the directly measured 21-d data. Body stores of vitamin A determined from either the calculated or directly measured 21-d enrichment data also showed agreement.Conclusion: Percentage enrichment at 3 d (but not at 6 h) can be used to evaluate vitamin A body stores in humans.