The role of vitamin D in the age of COVID-19: A systematic review and meta-analysis.

Background: Evidence recommends that vitamin D might be a crucial supportive agent for the immune system, mainly in cytokine response regulation against COVID-19. Hence, we carried out a systematic review and meta-analysis in order to maximise the use of everything that exists about the role of vitamin D in the COVID-19.

Methods: A systematic search was performed in PubMed, Scopus, Embase and Web of Science up to December 18, 2020.