Vitamin D insufficiency as a potential culprit in critical COVID-19 patients

Abstract

Background: As an immune modulator, vitamin D has been implicated in the coronavirus disease-2019 (COVID-19) outcome. We aim to systematically explore the association of vitamin D serum levels with COVID-19 severity and prognosis. Methods: The standardized mean difference (SMD) or odds ratio and 95% confidence interval (CI) were applied to estimate pooled results from six studies. The prognostic performance of vitamin D serum levels for predicting adverse outcomes with detection of the best cutoff threshold was determined by receiver operating characteristic curve analysis. Decision tree analysis by combining vitamin D levels and clinical features was applied to predict severity in COVID-19 patients. Results: Mean vitamin D serum level of 376 patients, was 21.9 nmol/L (95% CI = 15.36–28.45). Significant heterogeneity was found (I2 = 99.1%, p