Does Vitamin D deficiency increase the severity of COVID-19?

E. Kenneth Weir, Thenappan Thenappan, Maneesh Bhargava, Yingjie Chen

Research output: Contribution to journalArticlepeer-review

96 Scopus citations


The severity of coronavirus 2019 infection (COVID-19) is determined by the presence of pneumonia, severe acute respiratory distress syndrome (SARS-CoV-2), myocarditis, microvascular thrombosis and/or cytokine storms, all of which involve underlying inflammation. A principal defence against uncontrolled inflammation, and against viral infection in general, is provided by T regulatory lymphocytes (Tregs). Treg levels have been reported to be low in many COVID-19 patients and can be increased by vitamin D supplementation. Low vitamin D levels have been associated with an increase in inflammatory cytokines and a significantly increased risk of pneumonia and viral upper respiratory tract infections. Vitamin D deficiency is associated with an increase in thrombotic episodes, which are frequently observed in COVID-19. Vitamin D deficiency has been found to occur more frequently in patients with obesity and diabetes. These conditions are reported to carry a higher mortality in COVID-19. If vitamin D does in fact reduce the severity of COVID-19 in regard to pneumonia/ARDS, inflammation, inflammatory cytokines and thrombosis, it is our opinion that supplements would offer a relatively easy option to decrease the impact of the pandemic.

Original languageEnglish (US)
Pages (from-to)E107-E108
JournalClinical Medicine
Issue number4
StatePublished - Jul 2020

Bibliographical note

Publisher Copyright:
© Royal College of Physicians 2020. All rights reserved.


  • COVID 19
  • Coronavirus
  • Inflammation
  • Treg
  • Vitamin D

PubMed: MeSH publication types

  • Journal Article


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