Role of dietary supplements in treatment and prophylaxis of COVID-19: A Systematic Review

Coronaviruses are a family of viruses known to infect mammals and birds, belonging to the family Coronaviridae. Before the emergence of COVID-19, there were six different coronaviruses known to infect humans, four of which cause a mild common cold-type illness. The main objective of the study is to review the role of dietary supplements in treatment and prophylaxis of COVID-19. This study was conducted using a systematic search on Google scholar, Pubmed and Web of science published until 20th June 2020. The cited references of retrieved articles and previous reviews were also manually checked to identify any additional eligible studies.  All citations were imported into a bibliographic database and duplicates were removed. Title, abstract and then full-text of all articles were screened for eligibility. Vitamin   D  has  important   functions   beyond   those   of calcium and  bone metabolism that  include modulation  of the  innate  and  adaptive  immune  responses.  At least 1 billion   people   globally   have vitamin   D   deficiency. Vitamin   D   deficiency   and   insufficiency   makes   our population   more   vulnerable   and   more   susceptible   to develop     infectious     diseases especially     respiratory infections. It is concluded that the  research  has  yet  not  proved  that vitamin  D  is  effective  against  the  novel  Corona  virus,  it does   show   that vitamin   D   helps   to   protect   against respiratory tract infections.