Olivares Manuel, Pizarro Fernando, López de Romaña Daniel
Institute of Nutrition and Food Technology, University of Chile, Santiago, Chile.
Biol Trace Elem Res. 2013 Mar;151(3):471-5. doi: 10.1007/s12011-012-9582-7. Epub 2012 Dec 29.
The co-fortification of wheat flour with iron (Fe) and zinc (Zn) is a strategy used to prevent these deficiencies in the population. Given that Zn could interact negatively with Fe, the objective was to assess the effect of Zn on Fe absorption from bread prepared with wheat flour fortified with Fe and graded levels of Zn fortificant. Twelve women aged 30-43 years, with contraception and a negative pregnancy test, participated in the study. They received on four different days, after an overnight fast, 100 g of bread made with wheat flour (70 % extraction) fortified with 30 mg Fe/kg as ferrous sulfate (A) or prepared with the same Fe-fortified flour but with graded levels of Zn, as zinc sulfate: 30 mg/kg (B), 60 mg/kg (C), or 90 mg/kg (D). Fe radioisotopes ((59)Fe and (55)Fe) of high specific activity were used as tracers and Fe absorption iron was measured by the incorporation of radioactive Fe into erythrocytes.
The geometric mean and range of ± 1 SD of Fe absorption were: A= 19.8 % (10.5-37.2 %), B = 18.5 % (10.2-33.4 %), C = 17.7 % (7.7-38.7 %), and D = 11.2 % (6.2-20.3 %), respectively; ANOVA for repeated measures F = 5.14, p < 0.01 (Scheffè's post hoc test: A vs D and B vs D, p < 0.05). We can conclude that Fe is well absorbed from low extraction flour fortified with 30 mg/kg of Fe, as ferrous sulfate, and up to 60 mg/kg of Zn, as Zn sulfate. A statistically significant reduction of Fe absorption was observed at a Zn fortification level of 90 mg Zn/kg.
小麦粉同时强化铁（Fe）和锌（Zn）是一种用于预防人群中这些营养素缺乏的策略。鉴于锌可能与铁产生负面相互作用，本研究的目的是评估锌对用强化铁和不同锌强化水平的小麦粉制作的面包中铁吸收的影响。12名年龄在30 - 43岁、采取避孕措施且妊娠试验呈阴性的女性参与了该研究。她们在禁食过夜后的四个不同日子，分别食用100克用强化面粉制作的面包：一种是每千克强化面粉含30毫克硫酸亚铁形式的铁（A组），另一种是用相同的强化铁面粉，但添加不同水平硫酸锌形式的锌，分别为每千克30毫克（B组）、60毫克（C组）或90毫克（D组）。使用高比活度的铁放射性同位素（⁵⁹Fe和⁵⁵Fe）作为示踪剂，并通过放射性铁掺入红细胞来测量铁的吸收情况。
铁吸收的几何平均值及±1标准差范围分别为：A组 = 19.8%（10.5 - 37.2%），B组 = 18.5%（10.2 - 33.4%），C组 = 17.7%（7.7 - 38.7%），D组 = 11.2%（6.2 - 20.3%）；重复测量方差分析F = 5.14，p < 0.01（谢费尔事后检验：A组与D组以及B组与D组，p < 0.05）。我们可以得出结论，每千克含30毫克硫酸亚铁形式的铁以及每千克含高达60毫克硫酸锌形式的锌的低提取率面粉中的铁吸收良好。在锌强化水平为每千克90毫克时，观察到铁吸收有统计学意义的降低。
