CMAJ. 2013 Nov 19;185(17):E791-802. doi: 10.1503/cmaj.130628. Epub 2013 Oct 15.
Anemia is an important public health and clinical problem. Observational studies have linked iron deficiency and anemia in children with many poor outcomes, including impaired cognitive development; however, iron supplementation, a widely used preventive and therapeutic strategy, is associated with adverse effects. Primary-school-aged children are at a critical stage in intellectual development, and optimization of their cognitive performance could have long-lasting individual and population benefits. In this study, we summarize the evidence for the benefits and safety of daily iron supplementation in primary-school-aged children.
We searched electronic databases (including MEDLINE and Embase) and other sources (July 2013) for randomized and quasi-randomized controlled trials involving daily iron supplementation in children aged 5-12 years. We combined the data using random effects meta-analysis.
We identified 16 501 studies; of these, we evaluated 76 full-text papers and included 32 studies including 7089 children. Of the included studies, 31 were conducted in low- or middle-income settings. Iron supplementation improved global cognitive scores (standardized mean difference 0.50, 95% confidence interval [CI] 0.11 to 0.90, p = 0.01), intelligence quotient among anemic children (mean difference 4.55, 95% CI 0.16 to 8.94, p = 0.04) and measures of attention and concentration. Iron supplementation also improved age-adjusted height among all children and age-adjusted weight among anemic children. Iron supplementation reduced the risk of anemia by 50% and the risk of iron deficiency by 79%. Adherence in the trial settings was generally high. Safety data were limited.
Our analysis suggests that iron supplementation safely improves hematologic and nonhematologic outcomes among primary-school-aged children in low- or middle-income settings and is well-tolerated.
贫血是一个重要的公共卫生和临床问题。观察性研究表明，儿童缺铁和贫血与许多不良后果有关，包括认知发育受损；然而，铁补充剂作为一种广泛使用的预防和治疗策略，与不良反应有关。小学生正处于智力发展的关键阶段，优化他们的认知表现可能会给个人和人群带来持久的益处。在这项研究中，我们总结了在小学生中每日补铁的益处和安全性的证据。
我们搜索了电子数据库（包括 MEDLINE 和 Embase）和其他来源（2013 年 7 月），以确定涉及 5-12 岁儿童每日铁补充的随机和半随机对照试验。我们使用随机效应荟萃分析合并数据。
我们确定了 16501 项研究；其中，我们评估了 76 篇全文论文，并纳入了包括 7089 名儿童在内的 32 项研究。在纳入的研究中，31 项研究在中低收入国家进行。铁补充剂改善了总体认知评分（标准化均数差 0.50，95%置信区间[CI]0.11 至 0.90，p=0.01）、贫血儿童的智商（平均差异 4.55，95%CI0.16 至 8.94，p=0.04）和注意力和集中力的测量值。铁补充剂还改善了所有儿童的年龄调整身高和贫血儿童的年龄调整体重。铁补充剂将贫血风险降低了 50%，将缺铁风险降低了 79%。试验环境中的依从性通常较高。安全性数据有限。
我们的分析表明，铁补充剂在中低收入国家的小学生中安全地改善了血液学和非血液学结局，且耐受性良好。
