People who are vitamin D deficient are 14 times more likely to have severe COVID-19 and to die from the disease, according to research from scientists in Israel.

The peer-reviewed study, published in the journal PLoS ONE, looked at vitamin D levels before a person contracted COVID-19 and the disease’s severity and mortality.

Researchers from Azrieli Faculty of Medicine of Bar-Ilan University and the Galilee Medical Center found that patients with vitamin D deficiency (less than 20 ng/mL) were 14 times more likely to have a severe or critical case of COVID-19, compared to those with levels of vitamin D at more than 40 ng/mL.