Association between vitamin D and development of otitis media: A PRISMA-compliant meta-analysis and systematic review.

BACKGROUND: Nutrients related to serum vitamin D level were previously shown to be significantly associated with the risk of many chronic diseases. This study aimed to assess potential relationships between serum vitamin D level and otitis media (OM) risk. METHODS: PubMed, EMBASE, and Cochrane Library databases were searched till Aug 18, 2015 for studies of quantitative OM risk estimates in relation to serum vitamin D level. The odds ratio and weighted mean difference, with 95% confidence intervals (CIs), were used to measure the relationship between serum vitamin D level and OM risk. RESULTS: Of the 89 articles identified by database search, 5 studies reported data of 16,689 individuals were included in our meta-analysis. We noted participants with OM was associated with lower level of plasma vitamin D when compared with patients without OM (weighted mean difference -5.67; 95% CI -8.08 to -3.26, P < 0.001). Furthermore, as compared with control group, serum vitamin D level was not associated with the risk of OM (odds ratio 0.80, 95% CI 0.47-1.38, P = 0.425). Subgroup analyses suggested that participants with acute OM might associate with lower serum vitamin D level. CONCLUSIONS: Plasma vitamin D level might play an important role on the progression of acute OM, whereas no significant impact in patients with chronic OM.