Association between Vitamin D Level and Sensorineural Hearing Loss in Adults: Systematic Review and Meta-Analysis

Sensorineural hearing loss (SNHL) is the most common cause of hearing loss. Several studies have explored the association between vitamin D Levels and the incidence of SNHL. This systematic review and meta-analysis aim to assess the association between vitamin D and the SNHL in adult patients.This meta-analysis was conducted according to PRISMA guidelines. A comprehensive search was performed through PubMed, Embase, Cochrane, and Scopus on November 16, 2024, for all studies assessing the association between vitamin D levels and SNHL. The risk of bias was assessed using the Newcastle-Ottawa Scale (NOS). Meta-analysis was conducted using R software, with heterogeneity being assessed by the I2 statistic. Subgroup analysis was also performed. Five observational studies were included, with a total sample size of 1936 and a mean age of 61.9 years. Vitamin D levels were significantly lower in the SNHL group compared to healthy (MD = -9.50, I2 = 16.9%). The incidence of sufficient vitamin D levels was significantly lower in the SNHL group than in healthy (RR = 0.61, I2 = 85.3%). Subgroup analysis revealed a significantly lower risk ratio of sufficient vitamin D in the Sudden SNHL group than in the other types of SNHL. This meta-analysis suggests a significant association between vitamin D levels and the incidence of SNHL. Lower vitamin D levels were reported among SNHL patients. Further investigations are needed to account for the confounders of this association using less biased methodologies, such as cohort studies and clinical trials. Trail Registration: CRD420251072753.