Evidence of protective role of Ultraviolet-B (UVB) radiation in reducing COVID-19 deaths

Sci Rep. 2020 Oct 19;10(1):17705. doi: 10.1038/s41598-020-74825-z.

Abstract

Prior studies indicate the protective role of Ultraviolet-B (UVB) radiation in human health, mediated by vitamin D synthesis. In this observational study, we empirically outline a negative association of UVB radiation as measured by ultraviolet index (UVI) with the number of COVID-19 deaths. We apply a fixed-effect log-linear regression model to a panel dataset of 152 countries over 108 days (n = 6524). We use the cumulative number of COVID-19 deaths and case-fatality rate (CFR) as the main dependent variables and isolate the UVI effect from potential confounding factors. After controlling for time-constant and time-varying factors, we find that a permanent unit increase in UVI is associated with a 1.2 percentage points decline in daily growth rates of cumulative COVID-19 deaths [p < 0.01] and a 1.0 percentage points decline in the CFR daily growth rate [p < 0.05]. These results represent a significant percentage reduction in terms of daily growth rates of cumulative COVID-19 deaths (- 12%) and CFR (- 38%). We find a significant negative association between UVI and COVID-19 deaths, indicating evidence of the protective role of UVB in mitigating COVID-19 deaths. If confirmed via clinical studies, then the possibility of mitigating COVID-19 deaths via sensible sunlight exposure or vitamin D intervention would be very attractive.

Publication types

  • Observational Study

MeSH terms

  • Betacoronavirus / isolation & purification
  • COVID-19
  • Coronavirus Infections / mortality*
  • Coronavirus Infections / pathology
  • Coronavirus Infections / virology
  • Databases, Factual
  • Humans
  • Linear Models
  • Pandemics
  • Pneumonia, Viral / mortality*
  • Pneumonia, Viral / pathology
  • Pneumonia, Viral / virology
  • Radiation Dosage
  • SARS-CoV-2
  • Ultraviolet Rays*
  • Vitamin D / biosynthesis

Substances

  • Vitamin D