Dr. John Campbell | September 6, 2020 About 42% of the US population is vitamin D deficient 82% in black people 70% in Hispanics Association of Vitamin D Status and Other Clinical Characteristics With COVID-19 Test Results, (JAMA Open, 3rd September, Chicago) https://jamanetwork.com/journals/jama… Cohort study of 489 Patients who had a vitamin D level measured … Continue reading Vitamin D, First clinical trial