A new study has found an association between low levels of vitamin D and high numbers of COVID-19 cases and mortality rates across 20 European countries. The research, led by Dr. Lee Smith of Anglia Ruskin University, was published in the Aging Clinical and Experimental Research journal.

Previous research has indicated vitamin D plays a role in modulating acute respiratory infections by preventing white blood cells from over reacting to the infection by releasing too many inflammatory cytokines.

Now, scientists have found people in countries that have the highest mortality rates from COVID-19 like Italy and Spain, also had the lowest levels of vitamin D. Conversely, the highest levels of vitamin D were found in northern European countries, like Scandinavia, which was among the countries with the lowest mortality rates, according to Science Daily.

The authors speculate people in northern Europe take more vitamin D supplements along with cod liver oil and spend more time in the sun.

"We found a significant crude relationship between average vitamin D levels and the number of COVID-19 cases, and particularly COVID-19 mortality rates," Dr. Smith said. "Vitamin D has been shown to protect against acute respiratory infections, and older adults, the group most deficient in vitamin D, are also the ones most seriously affected by the virus."

According to the New York Post, the researchers wrote, "We believe that we can advise vitamin D supplementation to protect against SARS-CoV-2 infection."

SARS-Cov-2 is the pathogen that causes COVID-19.

Science Alert says vitamin D is a fat-soluble compound that we get either from food or supplementation, or our bodies manufacture from the sun's rays. While we are keenly aware of its role in preserving bone health, researchers are now looking at the vitamin's effect on our immune system.

The new European study might shed some light on its role in combatting the coronavirus.

"The most vulnerable group of populations for COVID-19 is also the one that has the most deficit in vitamin D," the authors wrote.