Solomons N W, Jacob R A
Am J Clin Nutr. 1981 Apr;34(4):475-82. doi: 10.1093/ajcn/34.4.475.
The change in the concentration of plasma zinc after oral administration of zinc was used as the index of zinc absorption in the study of the interaction of zinc and iron in the human intestine. With zinc sulfate as the source of inorganic zinc, and ferrous sulfate as the source of nonheme iron, a ratio of Fe/Zn of 1:1 slightly inhibited zinc absorption while Fe/Zn ratio of 2:1 and 3:1 substantially inhibited zinc uptake. No effect on zinc absorption was observed, however, when heme iron, as heme chloride, was ingested in a 3:1 Fe/Zn ratio with inorganic zinc. Atlantic oysters providing about 54 mg of zinc were consumed with or without 100 mg of ferrous iron; Fe/Zn ratio was 2:1. With this "organic" form of zinc, iron did not significantly affect zinc absorption. The evidence for competitive interaction of zinc and iron was strongest with nonheme iron and inorganic zinc. Thus, the possibility that intrinsic iron in formulas for feeding infants and in vitamin-mineral supplement might inhibit the absorption of zinc justifies concern about the Fe/Zn ratio in the formulation of these products.
在人体肠道锌与铁相互作用的研究中，口服锌后血浆锌浓度的变化被用作锌吸收的指标。以硫酸锌作为无机锌的来源，硫酸亚铁作为非血红素铁的来源，铁/锌比例为1:1时对锌吸收有轻微抑制作用，而铁/锌比例为2:1和3:1时则显著抑制锌的摄取。然而，当以氯化血红素形式的血红素铁与无机锌以3:1的铁/锌比例摄入时，未观察到对锌吸收有影响。食用提供约54毫克锌的大西洋牡蛎时，分别添加或不添加100毫克亚铁；铁/锌比例为2:1。对于这种“有机”形式的锌，铁对锌吸收没有显著影响。锌与铁竞争性相互作用的证据在非血红素铁和无机锌的情况下最为明显。因此，婴儿配方食品和维生素 - 矿物质补充剂中的固有铁可能抑制锌吸收，这一可能性使得人们有理由关注这些产品配方中的铁/锌比例。
