Estimation of nonheme-iron bioavailability from meal composition.
Estimation of nonheme-iron bioavailability from meal composition.
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DOI：
10.1093/ajcn/71.4.937
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发表时间：
2000-04
期刊：
影响因子：
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通讯作者：
M. Reddy;R. Hurrell;J. D. Cook
中科院分区：
文献类型：
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作者：
M. Reddy;R. Hurrell;J. D. Cook
背景：关于饮食因素对非血红素铁吸收的个体影响，有相当多的数据，但当它们出现在同一顿饭中时，它们的联合影响尚不清楚。目的我们的目标是根据已知促进或抑制食物铁吸收的因素的含量，预测美国常见的复合餐中铁的生物利用度。设计：采用外源性放射性铁标记法，对86名志愿者进行了25餐非血红素铁吸收的放射性同位素测量。通过生化分析测定非血红素铁、钙、抗坏血酸、多酚和植酸的含量；根据食物成分表估计能量和蛋白质的含量。动物组织含量以重量为基础，或从制造商那里获得。结果在调整铁吸收的铁状态差异后，经多元回归分析确定的铁吸收的显著生化预测因子是动物组织(P=0.0001)、植酸(P=0.0001)和抗坏血酸(P=0)。0441)。这3个变量合计解释了吸收变异的16.4%。在多元回归分析的基础上，我们建立了估算铁吸收的公式：LN吸收率，%(调整到血清铁蛋白浓度为30微克/L)=1.9786+(0.0123 x动物组织)-(0.0034 x植酸，mg)+(0.0065 x抗坏血酸，mg)。结论在评价的25种膳食中，只有动物组织、植酸和抗坏血酸的含量可用于评估非血红素铁的吸收。
BACKGROUND Considerable data are available on the individual effects of dietary factors on nonheme-iron absorption, but their combined effect when they are present in the same meal is not known. OBJECTIVE Our objective was to predict the bioavailability of iron from complex meals that are consumed commonly in the United States on the basis of the contents of factors that are known to promote or inhibit food iron absorption. DESIGN Radioisotopic measurements of nonheme-iron absorption from 25 meals were made in 86 volunteer subjects by using extrinsic radioiron labeling. The meal contents of nonheme iron, calcium, ascorbic acid, polyphenols, and phytic acid were determined by biochemical analysis; energy and protein contents were estimated from food-composition tables. Animal tissue content was based on weight or was obtained from the manufacturer. RESULTS After adjusting iron absorption for differences in iron status, the significant biochemical predictors of iron absorption as determined by multiple regression analysis were the contents of animal tissue (P = 0.0001), phytic acid (P = 0.0001), and ascorbic acid (P = 0. 0441). Collectively, these 3 variables accounted for 16.4% of the variation in absorption. On the basis of the multiple regression analysis, we developed the following equation to estimate iron absorption: Ln absorption, % (adjusted to serum ferritin concentration of 30 microg/L) = 1.9786 + (0.0123 x animal tissue in g) - (0.0034 x phytic acid in mg) + (0.0065 x ascorbic acid in mg). CONCLUSION For the 25 meals evaluated, only the contents of animal tissue, phytic acid, and ascorbic acid were useful for estimating nonheme-iron absorption.