He is also an Associate Professor of Epidemiology at the Harvard T.H. Chan School of Public Health. His research focuses on vitamin and mineral supplements and their role in major morbidity, including hypertension. Dr. Sesso is also an expert in the design, methodology, and conduct of randomized clinical trials, having tested vitamin C, vitamin E, a multivitamin, and cocoa extract, among others, as well as recently initiating a trial on magnesium and blood pressure.