From Fox News:
Researchers have discovered a strong correlation between vitamin D deficiency and mortality rates from the novel coronavirus, a new study reveals.
A research team led by Northwestern University analyzed data from hospitals and clinics across China, France, Germany, Italy, Iran, South Korea, Spain, Switzerland, the United Kingdom and the United States. Patients from countries with high COVID-19 mortality rates, such as Italy, Spain and the United Kingdom, had lower levels of vitamin D compared to patients in countries that were not as severely affected, according to the study.