Vitamin D and Its Potential Benefit for the COVID-19 Pandemic

Endocr Pract. 2021 May;27(5):484-493. doi: 10.1016/j.eprac.2021.03.006. Epub 2021 Mar 17.


Vitamin D is known not only for its importance for bone health but also for its biologic activities on many other organ systems. This is due to the presence of the vitamin D receptor in various types of cells and tissues, including the skin, skeletal muscle, adipose tissue, endocrine pancreas, immune cells, and blood vessels. Experimental studies have shown that vitamin D exerts several actions that are thought to be protective against coronavirus disease (COVID-19) infectivity and severity. These include the immunomodulatory effects on the innate and adaptive immune systems, the regulatory effects on the renin-angiotensin-aldosterone-system in the kidneys and the lungs, and the protective effects against endothelial dysfunction and thrombosis. Prior to the COVID-19 pandemic, studies have shown that vitamin D supplementation is beneficial in protecting against risk of acquiring acute respiratory viral infection and may improve outcomes in sepsis and critically ill patients. There are a growing number of data connecting COVID-19 infectivity and severity with vitamin D status, suggesting a potential benefit of vitamin D supplementation for primary prevention or as an adjunctive treatment of COVID-19. Although the results from most ongoing randomized clinical trials aiming to prove the benefit of vitamin D supplementation for these purposes are still pending, there is no downside to increasing vitamin D intake and having sensible sunlight exposure to maintain serum 25-hydroxyvitamin D at a level of least 30 ng/mL (75 nmol/L) and preferably 40 to 60 ng/mL (100-150 nmol/L) to minimize the risk of COVID-19 infection and its severity.

Keywords: 25-hydroxyvitamin D; COVID-19; SARS-CoV-2; vitamin D.

Publication types

  • Review

MeSH terms

  • COVID-19*
  • Humans
  • Pandemics* / prevention & control
  • SARS-CoV-2
  • Vitamin D
  • Vitamins


  • Vitamins
  • Vitamin D