If you wonder why COVID-19 strikes some countries more drastically than others, you’re not alone.
Researchers have been wondering the same thing.
And now they think they may have found the answer: varying Vitamin D levels.
Researchers from Northwestern University analyzed patient data from ten countries and found a correlation between low Vitamin D levels and hyperactive immune systems.
Cross section of date from Europe, Asia and America
Since Vitamin D strengthens the immune system and helps prevent overactive immune responses, the finding could explain several mysteries regarding COVID-19 deaths. Namely, why death rates are so much higher in some countries, and why children are unlikely to die from it.
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 researchers noted that patients from countries with high COVID-19 mortality rates—the US, Italy, Spain and the UK—had lower levels of Vitamin D compared to patients in countries that were not as severely affected.
Vitamin D deficiency is an epidemic
Earlier unrelated studies in the US—where COVID-19 deaths are the highest—have long established that the vast majority of the population have sub-optimal Vitamin D levels.
One study placed the number at 77% of the general population—with even higher rates among the elderly.
The Northwestern study was led by Vadim Backman, and was published in April on medRxiv, a pre-print server for health sciences.
Backman is the Walter Dill Scott Professor of Biomedical Engineering at Northwestern’s McCormick School of Engineering.
Backman and his team were inspired to research Vitamin D levels after noticing vast differences in COVID-19 mortality rates from country to country.
Some experts had theorized that differences in healthcare quality, age distributions in population, testing rates or different strains of the coronavirus might be responsible.
But Backman thought the answer lied elsewhere.
“None of these factors appears to play a significant role,” Backman said.
“The healthcare system in northern Italy is one of the best in the world. Differences in mortality exist even if one looks across the same age group.
“And, while the restrictions on testing do indeed vary, the disparities in mortality still exist even when we looked at countries or populations for which similar testing rates apply.
“Instead, we saw a significant correlation with Vitamin D deficiency,” he said.
Cytokine storm prevention
By analyzing publicly-available patient data from around the globe, Backman and his team discovered a strong correlation between Vitamin D levels and what is known as “cytokine storm.” Cytokine storm is a hyperinflammatory condition caused by an overactive immune system.
This is where Backman believes Vitamin D plays a major role. Not only does Vitamin D enhance the immune system, it also prevents the immune system from becoming dangerously “overactive.”
This means having healthy levels of Vitamin D can provide multi-layered protection against complications of COVID-19.
“Our analysis shows that it might be as high as cutting the mortality rate in half,” Backman said.
– – –