The Relationship Between Iron and Zinc Deficiency and Aphthous Stomatitis: A Systematic Review and Meta-Analysis.

Background: Recurrent aphthous stomatitis (RAS) is known as the most common ulcerative lesion in the oral mucosa. Aphthous has an unknown etiology and is considered a multifactorial disease. This study was conducted to investigate the relationship between iron and zinc deficiency and the occurrence of RAS. Materials and Methods: This systematic review and metaanalysis was performed according to the Preferred Reporting Items for Systematic Reviews and Metaanalyses (PRISMA) guidelines. Data were obtained through an electronic search in international databases, including PubMed, Medline, Embase, ISI Web of Science, Scopus, Springer, ProQuest, ScienceDirect, Clinical Key, and Google Scholar, and domestic Persian databases, including SID, Magiran, and Iran Medex, until April 2021. New-castle Ottawa Scale (NOS) was used to determine the eligibility of studies by evaluating the title and summary of the articles and a partial evaluation of the full text. Comprehensive Metaanalysis (CMA) software was used for data analysis. Results: Initially, a total of 1383 articles were retrieved, of which 941 were duplicate studies. Further, 384 studies were excluded after evaluation of the title and abstract, and 36 studies were excluded after considering the inclusion and exclusion criteria. Finally, 22 articles were included in the metaanalysis. The standardized mean difference value was -0.421 (-0.623--0.20) for iron factor, -0.309 (-0.463--0.154) for iron factor in men, -0.483 (-0.375--0373) for iron factor in women, and -0.955 (-0.282--1.628) for the zinc factor. Conclusion: In general, the serum iron level (in general, in male and female patients separately) and the zinc serum level in patients with RAS were significantly lower than those of healthy people.