ABSTRACT
While UV radiation is a skin carcinogen, this should not obscure the growing evidence that sunlight has significant health benefits, including impacts on cardiovascular and metabolic health. Epidemiological and mechanistic evidences for the importance of different wavelengths of sunlight, including blue light and UV radiation, are presented.
Subject(s)
Cardiovascular Diseases/prevention & control , Skin Neoplasms/epidemiology , Skin/radiation effects , Ultraviolet Rays , Vitamin D/biosynthesis , Cardiovascular Diseases/metabolism , Humans , Metabolic Networks and Pathways/radiation effects , Risk Assessment , Skin/metabolism , Skin/pathology , Skin Neoplasms/etiology , Skin Neoplasms/pathology , Skin Neoplasms/prevention & controlSubject(s)
COVID-19/epidemiology , Dermatology/standards , SARS-CoV-2 , Skin/radiation effects , Sunlight , Venereology/standards , Academies and Institutes , Erythema/etiology , Humans , Quarantine , Seasons , Skin/metabolism , Spain/epidemiology , Sunburn/etiology , Sunburn/prevention & control , Vitamin D/biosynthesisABSTRACT
Severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2), the causative agent of coronavirus disease 2019 (COVID-19), has become pandemic on March 11th, 2020. COVID-19 has a range of symptoms that includes fever, fatigue, dry cough, aches, and labored breathing to acute respiratory distress and possibly death. Health systems and hospitals have been completely rearranged since March 2020 in order to limit the high rate of virus spreading. Hence, a great debate on deferrable visits and treatments including phototherapy for skin diseases is developing. In particular, as regards phototherapy very few data are currently available regarding the chance to continue it, even if it may be a useful resource for treating numerous dermatological patients. However, phototherapy has an immunosuppressive action possibly facilitating virus infection. In the context of COVID-19 infection risk it is important to pointed out whether sunlight, phototherapy and in particular ultraviolet radiation (UV-R) constitute or not a risk for patients. In this review we aimed to focus on the relationship between UV-R, sunlight, phototherapy, and viral infections particularly focusing on COVID-19.
Subject(s)
COVID-19/epidemiology , Pandemics , SARS-CoV-2/radiation effects , Sunlight , Ultraviolet Rays , Vitamin D/physiology , Adaptive Immunity/radiation effects , Animals , Antimicrobial Cationic Peptides/biosynthesis , Antimicrobial Cationic Peptides/physiology , Cytokines/metabolism , Disease Models, Animal , Disease Susceptibility , Humans , Immunity, Innate/radiation effects , Immunosuppression Therapy , Interleukin-6/blood , Pathogen-Associated Molecular Pattern Molecules , SARS-CoV-2/genetics , SARS-CoV-2/pathogenicity , Skin Diseases/radiotherapy , Sunlight/adverse effects , Toll-Like Receptors/physiology , Ultraviolet Rays/adverse effects , Ultraviolet Therapy/adverse effects , Viruses/radiation effects , Vitamin D/biosynthesis , Vitamin D/therapeutic use , CathelicidinsABSTRACT
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.