Program in International and Community Nutrition, and Department of Nutrition, University of California, Davis, CA 95616, USA.
J Nutr. 2011 Jul;141(7):1369-74. doi: 10.3945/jn.110.136952. Epub 2011 May 11.
The responsiveness of plasma zinc concentration to zinc fortification is uncertain. Our objective in this study was to determine whether plasma zinc concentration changes in response to consuming zinc-fortified foods or liquid zinc supplements. We conducted a 4-wk double-blind, randomized trial among 132 healthy Senegalese men ≥ 18 y. Participants received 1 of 4 interventions: 1) (control) 200 g/d of wheat bread fortified with iron and folic acid, but not zinc, and a liquid multivitamin supplement without zinc between meals; 2) (zinc supplement) the same bread and the same multivitamin supplement with 15 mg zinc as ZnSO(4) added; 3) (moderate zinc fortification) the same bread cofortified with 7.5 mg zinc as ZnO and the same multivitamin supplement without zinc; or 4) (high zinc fortification) the same bread cofortified with 15 mg zinc as ZnO and the same multivitamin supplement without zinc. Fasting blood samples were collected twice at baseline and at d 15 and 29 of the intervention. There was no significant interaction between group and study day (P = 0.11). However, at d 15, the mean change in plasma zinc concentration in the zinc-supplemented group was greater than in the placebo and fortification groups ( 0.72 μmol/L vs. -0.09 to 0.03 μmol/L; P = 0.05). At d 29 there were no significant group-wise differences. Across all time points, the zinc-supplemented group was the only group where plasma zinc concentration increased from baseline (P = 0.006). These results suggest that plasma zinc concentration may not be a sufficiently sensitive indicator to evaluate short-term responses to zinc fortification.
血浆锌浓度对锌强化的反应性尚不确定。本研究的目的是确定食用强化锌的食物或液体锌补充剂是否会引起血浆锌浓度的变化。我们在塞内加尔 132 名年龄≥18 岁的健康男性中进行了为期 4 周的双盲、随机试验。参与者接受了以下 4 种干预措施之一：1）（对照组）每天食用 200 克强化铁和叶酸但不强化锌的面包和液体多种维生素补充剂，两餐之间不补充锌；2）（锌补充剂）相同的面包和相同的多种维生素补充剂，其中添加了 15 毫克硫酸锌（ZnSO(4)）形式的锌；3）（适度强化锌）相同的面包与氧化锌（ZnO）共强化，添加 7.5 毫克锌，同时添加相同的多种维生素补充剂但不含锌；4）（高强化锌）相同的面包与氧化锌（ZnO）共强化，添加 15 毫克锌，同时添加相同的多种维生素补充剂但不含锌。在基线和干预第 15 天和第 29 天采集两次空腹血样。组间和研究日之间没有显著的相互作用（P=0.11）。然而，在第 15 天，补锌组的血浆锌浓度变化均值大于安慰剂和强化组（0.72μmol/L vs. -0.09 至 0.03μmol/L；P=0.05）。在第 29 天，各组之间没有显著差异。在所有时间点，补锌组是唯一血浆锌浓度从基线升高的组（P=0.006）。这些结果表明，血浆锌浓度可能不是评估短期锌强化反应的敏感指标。
