I previously mentioned the potential of vitamin D to boost immune system defenses against COVID-19. Two recent studies have discovered a strong correlation between severe vitamin D deficiency and complications and/or mortality rates of COVID-19 patients.

The first – published in Aging Clinical and Experimental Research – found that COVID-19 infections and deaths were greater in countries where people had low vitamin D levels, such as Italy and Spain, compared to northern European countries where average vitamin D levels were higher. British researchers attributed the vitamin D differences to some southern Europeans having darker pigmentation, which reduces vitamin D synthesis, and northern Europeans consuming more cod liver oil and vitamin D supplements.

The second study appeared in the online journal medRxiv. Though not yet peer-reviewed, the study’s conclusion was the same: Low vitamin D levels were linked to a hyperactive immune system.

By analyzing publicly available patient data from around the globe, lead researcher and biomedical engineer Vadim Backman and his team at Northwestern University discovered a significant correlation between vitamin D levels and cytokine storm — a hyperinflammatory condition caused by an overactive immune system — as well as a correlation between vitamin D deficiency and mortality.

“Cytokine storm can severely damage lungs and lead to acute respiratory distress syndrome and death in patients,” said Ali Daneshkhah, a postdoctoral research associate in Beckman’s lab and the paper’s first author. “This is what seems to kill a majority of COVID-19 patients, not the destruction of the lungs by the virus itself. It is the complications from the misdirected fire from the immune system.”

As vitamin D enhances people’s innate immune systems as well as prevents them from becoming dangerously overactive, Backman and his team’s findings indicate that having healthy levels of vitamin D could protect patients against severe complications, including death, from COVID-19.

“Our analysis shows that it might be as high as cutting the mortality rate in half,” Backman said. “It will not prevent a patient from contracting the virus, but it may reduce complications and prevent death in those who are infected.”

Clinical trials to see if vitamin D can help infected patients are now underway. Meanwhile, I continue to be a proponent of taking vitamin D, vitamin C, and zinc supplements to protect your health should you contract COVID-19. Being healthy in general is the best thing you can do to protect your immune system.Stay safe, stay strong!