Association of Vitamin D with the Severity of Disease and Mortality in COVID-19: Prospective Study in Central India

BACKGROUND: Many factors have been proposed to be associated with the severity of disease and mortality in COVID-19. Vitamin D had recently been reviewed as one of these factors. AIM AND OBJECTIVES: To evaluate the association between Vitamin D and the disease severity and mortality in COVID-19. MATERIALS AND METHODS: After approval from Institutional Ethics Committee, this prospective cohort study was carried out in selected tertiary care teaching medical institutes of Central India. Participants were COVID-19 patients of the age group of 18 years and above admitted during the study period. They were categorized into four groups as asymptomatic (Group A), mild (Group B), moderate (Group C), and severe (Group D) based on clinical symptoms, respiratory rate, oxygen saturation, and chest imaging. Serum level of Vitamin 25(OH) D was measured using chemiluminescent immunoassay. The outcome of the disease was classified as recovery and death during hospitalization. The association of sociodemographic and medical characteristics with treatment outcome was studied using an appropriate statistical test. A full logistic regression model was built for the assessment of the relationship between treatment outcomes with Vitamin D level. Further, one receiver operating characteristic curve was developed to examine the prognostic significance of Vitamin D levels in COVID-19 patients. RESULTS: Out of 748 enrolled patients, 44 (5.88%), had severe disease (Group D). A total of 721 cases (96.39%) recovered and were discharged, whereas 27 (3.61%) died during hospitalization. Mean Vitamin D level was found to be significantly different in discharged patients compared to those who were deceased. Increasing age-adjusted odds ratio (AOR) (95% confidence interval [CI]=1.07 [1.02–1.12]), known hypertension AOR (95%CI) = 3.38 (1.13–10.08), and diabetes mellitus AOR (95%CI) =28.5 (6.04–134.13) were found to be significant predictors of death among COVID-19 patients. Increasing Vitamin D level was found to be protective against COVID-19-related death (AOR (95% CI = 0.87 [0.80–0.94]). CONCLUSION: Vitamin D was significantly associated with the disease severity and mortality in COVID-19.