Countries set RDAs for nutrients to guide intake. For many years, they have based these on the least amount of the nutrient needed to prevent clinical deficiency. For vitamin C, this is the amount necessary to prevent scurvy, a disease caused by vitamin C deficiency. Our work takes a different approach. We base RDAs on the functional impact of nutrient amount, or concentration. We explore nutrient functions in cultured cells or organelles. We conduct other studies on either animals or people. Our goals are to determine the ideal amount of nutrient for health and to treat disease. Although we use vitamin C as a model nutrient, the principles apply to many nutrients. Many countries now base their vitamin C RDAs on the results of our research.
Specifically, our laboratory explores the following questions:
- How does concentration of vitamin C change the biochemical functions of the nutrient in cells and organelles?
- What biochemical mechanisms transport vitamin C into and out of cells or tissues? What factors affect accumulation of vitamin C in these tissues?
- How do dose and frequency of vitamin C affect the nutrient’s concentrations in different tissues over time in both people and animals?
- 4. Does pharmacologic use of vitamin C, given intravenously as a drug, effectively treat cancer and infectious disease?
- Oral vitamin C does not result in high concentrations of vitamin C. In contrast, vitamin C injection results in very high concentrations. How do high concentrations increase the formation of hydrogen peroxide in tissues? Hydrogen peroxide formation is essential for treatment effects.
- How does vitamin C affect molecules in the body called free radicals? Free radicals are necessary for life but also influence the development of diseases, including cancer.
- How do health and disease relate to the regulation of glucose transport in cultured cells or organelles? How do health and disease relate to the regulation of glucose transport in animals or humans?
- What is the function of vitamin C in red blood cells in health and diabetes?