Hospitalised COVID-19 patients who were vitamin D sufficient, with a blood level of 25-hydroxyvitamin D of at least 30 ng/mL (a measure of vitamin D status), had a significant decreased risk for adverse clinical outcomes including becoming unconscious, hypoxia (body starved for oxygen), and death. In addition, they had lower blood levels of an inflammatory marker (C-reactive protein) and higher blood levels of lymphocytes (a type of immune cell to help fight infection).

For our comprehensive coverage and latest updates on COVID-19 click here.

"This study provides direct evidence that vitamin D sufficiency can reduce the complications, including the cytokine storm (release of too many proteins into the blood too quickly) and ultimately death from COVID-19," explained corresponding author Michael F. Holick, PhD, MD, professor of medicine, physiology, and biophysics and molecular medicine at Boston University School of Medicine.

A blood sample to measure vitamin D status (measured serum level of 25-hydroxyvitamin D) was taken from 235 patients were admitted to the hospital with COVID-19. These patients were followed for clinical outcomes including clinical severity of the infection, becoming unconscious, having difficulty in breathing resulting in hypoxia and death. The blood was also analyzed for an inflammatory marker (C-reactive protein) and for numbers of lymphocytes. The researchers then compared all of these parameters in patients who were vitamin D deficient to those who were vitamin D sufficient.