Abstract
Background Studies have reported that the rate of upper respiratory tract infections in children and adults is inversely related to serum vitamin D levels and supplementation with vitamin D reduces the incidence of this infection. This study aimed to examine if vitamin D serum levels were a risk factor for recurrent tonsillitis among adult patients. Methods Retrospective comparative analysis was carried out on 100 patients diagnosed with recurrent tonsillitis with 100 age- and sex-matched individuals as controls between June 2016 and May 2022. Tonsillar size was assessed based on Brodsky grading system. Serum levels of 25-hydroxy (25(OH)) vitamin D, total calcium, iron, hemoglobin, C-reactive protein (CRP), and erythrocyte sedimentation rate (ESR) were analyzed. Results There was a statistically significant low vitamin D levels in tonsil size grades III+IV compared to grade I+II (p <0.001) among cases. There was a significantly lower serum value for 25(OH) vitamin D in the cases as compared to the control group (p <0.001). A high percentage (68%) of cases had vitamin D deficiency (<20 ng/mL) and this was statistically significant (p <0.001). There were statistically significant higher values of CRP and ESR among cases compared to the control group (p <0.001). At a cut off (≤21.2), serum vitamin D levels achieved 78% sensitivity, 65% specificity (p <0.001) to differentiate cases from controls. Following logistic regression analysis, the level of vitamin D was the only significant risk factor. Conclusion Findings from our study also suggest an association between recurrent tonsillitis among our adult cohorts and low serum 25(OH) vitamin D levels. Therefore, we opine that serum vitamin D levels should be considered in the management of adult patients with tonsillitis.