US Pharm. 2020;45(6):1.

It seems that vitamin D plays a role in impacting myriad health conditions. Now, there might be another, very significant one to add to the list: After studying global data from the COVID-19 pandemic, researchers have discovered a strong correlation between severe vitamin D deficiency and mortality rates.

Led by Northwestern University, the research team conducted a statistical analysis of data from hospitals and clinics across China, France, Germany, Italy, Iran, South Korea, Spain, Switzerland, the United Kingdom, and the United States. (The research is available on medRxiv, a preprint server for health sciences.)

The researchers noted that patients from countries with high COVID-19 mortality rates, such as Italy, Spain, and the U.K., had lower levels of vitamin D compared with patients in countries that were not as severely affected. The scientists caution, however, everyone need not begin hoarding the vitamin. Vadim Backman, the Walter Dill Scott Professor of Biomedical Engineering at Northwestern University’s McCormick School of Engineering, who led the research, said, “This needs further study, and I hope our work will stimulate interest in this area. The data also may illuminate the mechanism of mortality, which, if proven, could lead to new therapeutic targets.”

Dr. Backman and his team were inspired to examine vitamin D levels after detecting unexplained, country-to-country differences in COVID-19 mortality rates. Some hypothesized that differences in healthcare quality, age distributions in population, testing rates, or different strains of the coronavirus might be the reason, but Dr. Backman remained skeptical.

“None of these factors appears to play a significant role,” he said.

By analyzing publicly available, worldwide patient data, Dr. Backman and his team discovered a strong correlation between vitamin D levels and cytokine storm—an overactive immune system–triggered hyperinflammatory condition—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,” explained Ali Daneshkhah, a postdoctoral research associate in Dr. Backman’s laboratory 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.”

This is the specific, major role that Dr. Backman believes vitamin D plays. Not only does vitamin D enhance immunity; it also prevents immune systems from becoming dangerously overactive. 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,” he said.

To comment on this article, contact