Ultraviolet UVA rays make up 95 percent of the Sun’s UV light and can penetrate more deeply into the skin.
People living in areas with the highest level of exposure to UVA rays had a lower risk of death from Covid-19 compared to those with lower levels, revealed the study published in the British Journal of Dermatology.
The analysis was repeated in England and Italy with the same results.
But nitric oxide released by the skin due to sunlight exposure could be a reason as this can likely reduce the ability of SARS CoV2, the virus causing Covid-19, to replicate, as has been found in some lab studies, they noted.
Previous studies have established the link between increased sunlight exposure and improved cardiovascular health, with lower blood pressure and fewer heart attacks. With heart disease being a known risk factor for mortality rate from Covid-19, this could also explain the latest findings.
The team compared all recorded deaths from Covid-19 in the US from January to April 2020 with UV levels for 2,474 US counties for the same time period.
Due to the observational nature of the study, it is not possible to establish cause and effect. However, it may lead to interventions that could be tested as potential treatments, the researchers said.