{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,11,2]],"date-time":"2026-11-02T16:37:21Z","timestamp":1793637441957,"version":"4.5.1"},"reference-count":41,"publisher":"MDPI AG","issue":"24","license":[{"start":{"date-parts":[[2022,12,15]],"date-time":"2022-12-15T00:00:00Z","timestamp":1671062400000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"Sanming Project of Medicine in Shenzhen","award":["SZSM202111001"],"award-info":[{"award-number":["SZSM202111001"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Nutrients"],"abstract":"<jats:p>Background: There is abundant evidence showing that iron deficiency is closely linked with delayed brain development, worse school performance, and behavioral abnormalities. However, evidence on the impact of iron supplementation among children and adolescents in low- and middle-income countries (LMICs) has been inconsistent. This study aims to examine the effect of oral iron supplementation on cognitive function among children and adolescents in LMICs. Methods: A systematic review and meta-analysis was conducted to examine the impact of iron supplementation on cognitive function (including intelligence, attention, short-term memory, long-term memory, and school performance) among children and adolescents aged 5 to 19. We searched PubMed, Embase, Web of Science, CINAHL, and references of related articles published from the inception of the databases to 1 May 2022. Random-effects pooled standardized mean difference (SMD) with 95% confidence intervals (CIs) were calculated to estimate the effect of iron supplementation on cognitive function. We also investigated the heterogeneity of the effects using subgroup and meta-regression analyses. This review was registered with PROSPERO (CRD42020179064). Results: Nine studies with 1196 individual participants from five countries were identified and included. Iron had a positive impact on intelligence test scores among children and adolescents (SMD = 0.47, 95% confidence interval [CI]: 0.10, 0.83). Meta-regression showed that the intelligence test scores improved with increasing the iron supplement dose (odds ratio [CI] = 1.02, 95% CI: 1.00, 1.04). There were no significant effects on attention, short-term memory, long-term memory, or school performance. Conclusions: Oral iron intake can improve the intelligence test scores of children and adolescents in LMICs and should be considered for future nutritional interventions.<\/jats:p>","DOI":"10.3390\/nu14245332","type":"journal-article","created":{"date-parts":[[2022,12,16]],"date-time":"2022-12-16T02:54:02Z","timestamp":1671159242000},"page":"5332","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":39,"title":["Effect of Oral Iron Supplementation on Cognitive Function among Children and Adolescents in Low- and Middle-Income Countries: A Systematic Review and Meta-Analysis"],"prefix":"10.3390","volume":"14","author":[{"given":"Zekun","family":"Chen","sequence":"first","affiliation":[{"name":"Vanke School of Public Health, Tsinghua University, Beijing 100084, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Huanhuan","family":"Yang","sequence":"additional","affiliation":[{"name":"Vanke School of Public Health, Tsinghua University, Beijing 100084, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-3369-5972","authenticated-orcid":false,"given":"Dongqing","family":"Wang","sequence":"additional","affiliation":[{"name":"Department of Global Health and Population, Department of Nutrition, Harvard T.H. Chan School of Public Health, Harvard University, Boston, MA 02115, USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-3203-3638","authenticated-orcid":false,"given":"Christopher R.","family":"Sudfeld","sequence":"additional","affiliation":[{"name":"Department of Global Health and Population, Department of Nutrition, Harvard T.H. Chan School of Public Health, Harvard University, Boston, MA 02115, USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Ai","family":"Zhao","sequence":"additional","affiliation":[{"name":"Vanke School of Public Health, Tsinghua University, Beijing 100084, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Yiqian","family":"Xin","sequence":"additional","affiliation":[{"name":"Duke Global Health Institute, Duke University, Durham, NC 27705, USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Jiawen Carmen","family":"Chen","sequence":"additional","affiliation":[{"name":"Department of Population and Public Health Sciences, Keck School of Medicine, University of Southern California, Los Angeles, CA 90089, USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Wafaie W.","family":"Fawzi","sequence":"additional","affiliation":[{"name":"Department of Global Health and Population, Department of Nutrition, Harvard T.H. Chan School of Public Health, Harvard University, Boston, MA 02115, USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Yan","family":"Xing","sequence":"additional","affiliation":[{"name":"Department of Pediatrics, Peking University Third Hospital, Beijing 100191, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Zhihui","family":"Li","sequence":"additional","affiliation":[{"name":"Vanke School of Public Health, Tsinghua University, Beijing 100084, China"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2022,12,15]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"440s","DOI":"10.1093\/jn\/130.2.440S","article-title":"Iron requirements in adolescent females","volume":"130","author":"Beard","year":"2000","journal-title":"J. Nutr."},{"key":"ref_2","unstructured":"Gupta, A., Mohammed, S., Saxena, A., Rahi, S., and Mohan, A. (2022, November 20). 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