ABSTRACT
Corona Virus Disease-2019 or COVID-19 is the ongoing global pandemic caused by SARS-COV-2 (Severe Acute Respiratory Syndrome Corona Virus 2) which affects mostly the respiratory system in humans, producing mild symptoms like fever, dry cough to severe life threatening complications like pneumonia, ARDS (Acute Respiratory Distress Syndrome) and others, ultimately leading to death. Elder population and people with different co morbidities like hypertension, diabetes, cardio vascular diseases or chronic kidney disease are more susceptible to get infected by this deadly virus. Amidst plenty of explored and unexplored risk factors which exacerbate COVID complications, reports from different European and other countries have identified poor serum concentration of vitamin D (25-hydroxy cholecalciferol <25nmol/L) is one of them. Vitamin D deficiency is found among elderly and black population; in home residents and even in various comorbidities. Besides its well defined role on musculo-skeletal system, vitamin D has prominent effects on host immune response, Renin-angiotensis-System (RAS) and many other extra-skeletal activities- which might serve the link between vitamin D deficiency and fatal outcome of COVID-19. Clinically it is proved that supplementation of this vitamin is beneficial to treat acute respiratory tract infection, tuberculosis, pneumonia or ARDS. Though the therapeutic effect of vitamin D supplementation in COVID-19 is still a subject of further investigations but when vitamin D deficiency is prevalent, then supplementation of vitamin D or consuming rich sources of vitamin D would likely to be beneficial for reducing the risk of the disease or its severity.
