Vitamin D and COVID-19: is there a role?

The COVID-19 pandemic requires a rapid understanding of the pathogenesis of the spectrum of the disease and factors associated with varied clinical presentations. Immune dysregulation with a cytokine storm (CS) progressing to ARDS with resemblance to sHLH is suggested as a main cause of tissue injury. Low levels of vitamin D were observed in COVID-19 cases with higher incidence of mortality in 20 European countries, increased risk of severity in COVID-19 contributing to ARDS or fulminant myocarditis and micro vascular thrombosis is proposed. Vitamin D may be protective against acute respiratory tract infections, as it regulates the inflammatory cytokine response of respiratory epithelial cells and macrophages, suppress CS and other manifestations seen in SARS-Cov-2. Hence, it is suggested as one of the therapies in SARS-CoV-2 infection. Major research gaps are identified globally in clinical management and this relationship. There is an imperative requisite to understand the interplay of markers in SARS-CoV-2, its risk factors and potential role of vitamin D to improve clinical outcome by pandemic of COVID-19. We therefore perform this review for understanding the pathophysiology of SARS-CoV-2 infections and the role of vitamin D in combating it.