Vitamin D micronutrient and COVID-19: the missing link

Abstract

The current onset and expeditious increase of COVID-19, caused by severe acute respiratory distress syndrome coronavirus (SARS-CoV-2), has established a global health predicament. Declared as pandemic and public health emergency by the World Health Organization (WHO), it follows an extremely heterogeneous course from mild flu like symptoms to severe acute respiratory distress syndrome. This outbreak intimidates the public with human to human escalation, which is the primary concern worldwide with a still unforeseeable result. With limited data on plausible therapy and vaccination, it is significant to unravel the virulence mechanism of SARS-CoV-2 to delineate chemoprevention that might curb the fatal outcome. It may be acknowledged here that the primary stage of disease prevention depends on the protective immune response to eliminate the virus. This postulation kindles interest in the intervention of vitamin D micronutrient, which might unfold the feasibility of slowing disease advancement and decreasing the risk of mortality. Taking into account, the wide spectrum of beneficial effects ascribed to vitamin D like antiviral, immunomodulatory, anti-inflammatory, and antioxidant action, it can be administered to affect immune cell proliferation and angiotensin-converting enzyme (ACE) 2 expression, which is the basis of pathogenesis of transmission of SARS-CoV-2. Recently, several observational clinical and epidemiological studies underline the hypothesis regarding mean vitamin D level and COVID-19 mortality. More so some retrospective analysis reported the correlation between vitamin D level and disease severity. Nevertheless, potential clinical researches and randomised control trials are recommended in COVID-19 patients with different levels of disease extremity to appraise the useful outcomes.