Vitamin D and COVID-19: An Overview of Recent Evidence

Int J Mol Sci. 2021 Sep 29;22(19):10559. doi: 10.3390/ijms221910559.


The novel coronavirus severe acute respiratory syndrome (SARS-CoV-2) has progressed rapidly from an outbreak to a global pandemic, with new variants rapidly emerging. Coronavirus disease 2019 (COVID-19), the disease resulting from SARS-CoV-2 infection, can lead to multiorgan damage. Due to the extremely contagious and fatal nature of the virus, it has been a priority of medical research to find effective means of treatment. Amid this search, the role of vitamin D in modulating various aspects of the innate and adaptive immune system has been discussed. This review aims to consolidate the research surrounding the role of vitamin D in the treatment and prevention of COVID-19. While there are some conflicting results reported, the consensus is that vitamin D has a host of immunomodulatory effects which may be beneficial in the context of COVID-19 and that low levels of vitamin D can result in dysfunction of crucial antimicrobial effects, potentially contributing to poor prognosis. Studies also show that the effects of low vitamin D can be mitigated via supplementation, although the benefits of vitamin D supplementation in the treatment of COVID-19 remain controversial.

Keywords: COVID-19; SARS-CoV-2; coronavirus; immunity; infection; review; vitamin D.

Publication types

  • Review

MeSH terms

  • Adaptive Immunity / drug effects
  • Animals
  • COVID-19 / immunology
  • COVID-19 / prevention & control*
  • Humans
  • Immunity, Innate / drug effects
  • Immunologic Factors / pharmacology
  • Immunologic Factors / therapeutic use*
  • SARS-CoV-2 / drug effects
  • SARS-CoV-2 / immunology
  • Vitamin D / pharmacology
  • Vitamin D / therapeutic use*
  • Vitamins / pharmacology
  • Vitamins / therapeutic use*


  • Immunologic Factors
  • Vitamins
  • Vitamin D