The prevalence of vitamin D—or more to the point, the lack of this vital nutrient—has been associated with coronavirus survival for months, but a group of Italian doctors are adding more data to that body of research. The researchers behind this new study evaluated 42 patients with acute respiratory failure due to COVID-19, who had all been treated in the Respiratory Intermediate Care Unit (RICU) in a clinic in the Bari province in March and April. What the researchers found was that after 10 days of hospitalization, patients with severe vitamin D deficiencies had a 50 percent chance of dying from the virus, while those with vitamin D levels of at least 10 ng/mL had only a 5 percent mortality risk.ae0fcc31ae342fd3a1346ebb1f342fcb This new report is consistent with a May study by researchers at Northwestern University who also found a correlation between vitamin D deficiency and coronavirus-related deaths. Vadim Backman, PhD, who led the Northwestern study, concluded that increasing vitamin D to healthy levels could potentially cut a patient’s mortality rate in half. It’s been estimated that about 20 percent of the U.S. population has deficient or inadequate levels of vitamin D. And unfortunately, vitamin D deficiency can be difficult to diagnose because its symptoms are consistent with many other health issues, including depression and insomnia. The most reliable way to find out if you are deficient in vitamin D is to see a medical professional and get a blood test. And if you are in fact vitamin D deficient, besides getting some more sunlight, you can increase your vitamin D levels by eating oil-rich fish like salmon and sardines, eggs, milk, cereals, and certain juices, according to the CDC. RELATED: For more up-to-date information, sign up for our daily newsletter. In this latest study out of Italy, the researchers note that their findings “suggest a possible role for the vitamin D supplementation in the supportive treatment of COVID-19 patients.” So, while vitamin D cannot prevent you from getting the virus, keeping your levels in a healthy range can help you avoid a worst-case scenario if you do contract coronavirus. And for more about your COVID risk, check out 24 Things You’re Doing Every Day That Put You at COVID Risk.