Sunbathing could cut the risk of dying from Covid, according to new research.
Scientists say it causes the skin to release a chemical that alleviates symptoms, and the phenomenon also dampens inflammation.
Dr Richard Weller, of the University of Edinburgh, said of the study: “There is still so much we don’t understand about Covid-19, which has resulted in so many deaths worldwide.
“These early results open up sunlight exposure as one way of potentially reducing the risk of death.”
The findings are based on people living in England, Italy and the US.
The study found regions in the US with the highest level of UVA rays – which makes up 95 per cent of the sun’s ultraviolet light – had fewer Covid deaths.
It looked at data from January to April 2020 across 2,474 counties. The analysis was repeated in England and Italy with the same results.
In sunny areas, coronavirus mortality rates fell and the findings could act as a simple public health intervention, say the Scottish team.
Co-author Professor Chris Dibben, chair in health geography at Edinburgh, said: “The relationship between Covid-19 mortality, season and latitude has been quite striking.
“Here we offer an alternative explanation for this phenomenon.”
The researchers took into account factors known to be associated with increased exposure to the virus and risk of death.
These included age, ethnicity, socioeconomic status, population density, air pollution, temperature and levels of infection in local areas.
Reduction in deaths could not be explained by higher levels of vitamin D. Only areas with insufficient levels of UVB to produce it in the body were included.
Prof Dibben and colleagues say sunlight exposure also causes the skin to release nitric oxide which could be an explanation.
It may, scientists say, reduce the virus’ ability to replicate – as has been demonstrated in lab experiments.
Previous research from the same group has shown sunlight also improves cardiovascular health.
It reduces blood pressure – protecting against heart attacks. Cardiovascular disease is a known complication from Covid-19.
They have also found it relieves eczema by releasing nitric oxide into the bloodstream.
The chemical activates specialised immune cells called regulatory T cells which douse inflammation.
The latest study published in the British Journal of Dermatology, may lead to potential Covid treatments, added the researchers.