Deficiency of vitamin D increases the likelihood of being infected with the Covid-19 virus, say researchers at the University of Chicago Medicine. The research team evaluated 489 UChicago Medicine patients whose vitamin D levels were measured within a year before being tested for Covid-19. Patients with untreated vitamin D deficiency were almost twice as likely to test positive for Covid-19 as compared to patients who had sufficient levels of this vitamin. “Vitamin D is important to the function of the immune system and vitamin D supplements have previously been shown to lower the risk of viral respiratory tract infections. Our statistical analysis suggests this may be true for the Covid-19 infection,” says Dr. David Meltzer, chief of hospital medicine at UChicago Medicine and lead author of the study. According to Dr. Meltzer understanding whether treating Vitamin D deficiency changes Covid-19 risk could be of great importance. “Vitamin D is inexpensive, generally very safe to take, and can be widely scaled,” he says