key: cord-0726203-it9u74yb
authors: Wang, Xing; Zhang, Yu; Fang, Fang
title: Role of vitamin D in COVID‐19 infections and deaths
date: 2021-02-07
journal: J Evid Based Med
DOI: 10.1111/jebm.12421
sha: a89e928cc9a583be33891a1ba28d94eb901b0d0a
doc_id: 726203
cord_uid: it9u74yb

nan

Dear Editor, As of August 31, 2020, there have been more than 25 million officially reported confirmed cases of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection in the world (updated data available at https://gisanddata.maps.arcgis.com/apps/opsdashboard/index. html#/bda7594740fd40299423467b48e9ecf6). Currently, the best strategies for mitigating the damage from COVID-19 involve policies to encourage social distancing, contact tracing, and the wearing of masks to reduce the spread of the coronavirus. There is no effective treatment for symptomatic patients, with various forms of supportive care being an active area of research. However, certain disparities in the case loads of different ethnicities and different populations are beginning to emerge. Although there are many other factors that are intertwined, one hypothesis at the present moment is that vitamin D supplementation might hold promise as a preventive or therapeutic agent for COVID-19 since the striking overlap between risk factors for severe COVID-19 and vitamin D deficiency, including obesity, older age, and Black or Asian ethnic origin.

Vitamin D is a fat-soluble vitamin that can regulate calcium and phosphorus metabolism, affecting bone growth and muscle health. It also plays significant role in the maintenance of immune homeostasis. Low vitamin D status is associated with many non-communicable diseases. A variety of studies have shown that 1,25-(OH) 2 D, the active vitamin D metabolite, is involved in the development of several immune-related diseases, such as psoriasis, type 1 diabetes, multiple sclerosis, rheumatoid arthritis, and so on. 1 Low levels of vitamin D is also associated with increased susceptibility to infectious disease. As a regulator of innate immunity, it could regulate the resistance to viruses, including induction of antimicrobial peptides and autophagy. Vitamin D can also be used as an adaptive immune regulatory factor. The active supplementation can be shown to provide a benefit in reducing cases or mortalities at the epidemiological level, it is unlikely that vitamin D alone can be a treatment or prevention for COVID-19 infection. Until then, the only certainty is that vitamin D supplementation for individuals deficient in vitamin D is known to be safe, cost-effective, and is of benefit for general immune system function and bone health.

The authors declare no conflict of interest. 

Immunologic effects of vitamin D on human health and disease

Vitamin D supplementation to prevent acute respiratory tract infections: systematic review and meta-analysis of individual participant data

Role of vitamin D in preventing of COVID-19 infection, progression and severity

Evidence that vitamin D supplementation could reduce risk of influenza and COVID-19 infections and deaths

Association of vitamin D deficiency and treatment with COVID-19 incidence