A new research study at the University of Chicago Medicine has found that when it comes to COVID-19, having vitamin D levels above those traditionally considered sufficient may lower the risk of infection. The study, published March 19 in JAMA Open Network, retrospectively examined the relationship between vitamin D levels and likelihood of testing positive for COVID-19. While levels of 30 ng/ml or more are usually considered “sufficient,” the authors found that Black individuals who had levels of 30 to 40 ng/ml had a 2.64 times higher risk of testing positive for COVID-19 than people with levels of 40 ng/ml or greater. Statistically significant associations of vitamin D levels with COVID-19 risk were not found in white people. The study looked at data from over 3,000 patients at UChicago Medicine who had had their vitamin D levels tested within 14 days before a COVID-19 test. The research team is now recruiting participants for two separate clinical trials testing the efficacy of vitamin D supplements for preventing COVID-19. This research is an expansion of an earlier study showing that a vitamin D deficiency (less than 20 ng/ml) may raise the risk of testing positive for COVID-19.