Serum zinc level and children's asthma: A systematic and meta-analysis review article

Background: Asthma is a chronic inflammatory respiratory disorder. Nutritional conditions affect allergic diseases such as asthma. The aim of this study was to review the serum zinc level in children with asthma. Methods: This is a review article found in databases such as Google, PubMed, SID, Irandoc, Scopus and up-to-date. Key words for search included zinc, asthma, children and pediatric. There was no time limitation for the search. These articles on zinc levels in asthmatic children were meta-analyzed. Results: Out of the 40 articles, 19 articles were excluded and 21 articles were included in this analysis. 15 articles evaluated serum zinc levels, 4 articles on hair zinc levels, one article evaluated nail zinc levels and another on zinc level in erythrocyte cells in children with asthma. Only 3 articles evaluated effects of zinc supplement treatment in children with asthma. Meta-analysis of studies showed that there was no significant difference between the standard mean differences of zinc level in asthmatic patients compared to the control group. We cannot analyze the association between zinc levels in hair and nail in children with asthma. All clinical trial studies show that zinc supplement improves clinical manifestations of asthma and patient's pulmonary function test. Conclusion: We found that the mean serum zinc level difference is not significant in children with asthma than healthy control group and it seems that there is no relation between mean serum zinc level and severity of asthma in children.