Dublin, UK - Data from hard-hit countries such as the US, Britain, and Italy suggest sunnier areas "are associated with fewer deaths from Covid-19," according to scientists at the University of Edinburgh.

Published in the British Journal of Dermatology, the study said "higher ambient UVA [ultraviolet A radiation] exposure" is "associated with lower Covid-19 specific mortality."

The team compared deaths linked to Covid-19 in the US from January to April 2020 with UV levels for almost 2,500 US counties, before replicating the methodology for the UK and Italy.

The three countries have reported some of the world's highest pandemic-related death numbers, both per capita and absolute, though fatalities dropped significantly during the summer months.

Most countries in Asia and Africa have reported relatively low deaths per capita throughout the pandemic.

Paper co-author Chris Dibben 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 said they controlled for the possible impact of Vitamin D, which has been widely cited as a Covid-19 inhibitor and is called "the sunshine vitamin" due to the human body producing more of it when skin is exposed to sunlight.

"Sun exposure may reduce death from Covid-19 independently of vitamin D," the team said.

Other recent findings have lent weight to the theory that time spent outdoors diminishes the likelihood of Covid illness.

Irish health officials said on Monday only 0.1% of all the country's coronavirus cases could be linked to outdoor activity, much of which is nonetheless banned under the current third pandemic lockdown.