William B. Grant, Ph.D. is founder and president, Sunlight, Nutrition, and Health Research Center, San Francisco, California and a leading expert on vitamin with over 275 publications listed at pubmed.gov. His primary research interests are identifying and quantifying the risk-modifying factors for chronic and infectious diseases, with a particular interest in ultraviolet irradiance and vitamin D. In this interview we explore vitamin D research and clinical use with particular focus on the relationship between vitamin D and viral respiratory tract infections including COVID-19.

Further reading:

Grant WB, Lahore H, McDonnell SL, et al. Evidence that Vitamin D Supplementation Could Reduce Risk of Influenza and COVID-19 Infections and Deaths. Nutrients. 2020;12(4):988.

Grant, WB. Preventing a covid-19 pandemic: Can vitamin D supplementation reduce the spread of COVID-19? Try first with health care workers and first responders. BMJ. 2020.