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Charles B Stephensen

Center Director


430 West Health Sciences Drive

University of California, Davis

Davis, CA 95616

Phone: (530) 304-3528



    • Charles B. Stephensen, Ph.D., is a Research Leader at the USDA Western Human Nutrition Research Center (WHNRC) in Davis, CA and an Adjunct Professor of Nutrition at U.C. Davis. He has a longstanding interest in research on the effect of nutrition on immune function, with a particular focus on the effects of vitamin A, as well as vitamin D, on immune function. Recent work has focused on vitamin D and immune function in pregnancy, and on the health benefits of vitamin D supplementation during HIV infection. Ongoing work at the WHNRC is examining the associations of typical diet with the intestinal microbiota and the potential impact of the microbiota on systemic immune activation and inflammation. Many of Dr. Stephensen’s studies have involved international collaborations, particularly in Peru and Bangladesh. For example, he has collaborated with several investigators on different projects at the International Centre for Diarrhoeal Disease Research, Bangladesh (icddr,b) since 1986. These studies have examined the association of gastric acid production with risk of development of cholera, the effect of infectious diseases, such as diarrhea, dysentery and pneumonia, on vitamin A metabolism in infants and children, and effect of vitamin A supplementation on immune function. Recent studies have also focused on the association of the gut microbiota community composition of healthy infants with response to early childhood immunization. Dr. Stephensen obtained a B.S. degree in Biochemistry at the University of California, Davis, M.S. degree in Human Nutrition at Cornell University and a Ph.D. in Immunology and Infectious Diseases at the Johns Hopkins University School of Hygiene and Public Health in Baltimore, Maryland. He trained as a postdoctoral fellow in Virology at the Uniformed Services University of the Health Sciences in Bethesda, Maryland. Dr. Stephensen was a faculty member in the Department of International Health, School of Public Health at the University of Alabama at Birmingham for 10 years and also served as acting Director of the Sparkman Center for International Public Health Education. In 1998 he moved to the WHNRC. Dr. Stephensen is a member of the editorial board of the Journal of Nutrition and has authored over 100 scientific publications.