Submitted to: Book Chapter
Publication Type: Book / Chapter
Publication Acceptance Date: 3/1/1996
Publication Date: N/A
Interpretive Summary: This is a review of studies of human vitamin C metabolism. These studies are important, because recommended daily dietary allowances for vitamin C are based on the results of these studies. This review describes these human nutrition studies, and evaluates their strengths and weaknesses. The review also summarizes the information on the factors (such as sex, smoking, and pregnancy) that influence vitamin C metabolism and requirements. Finally, it discusses gaps in the scientific knowledge of vitamin C metabolism, and directions for future research in this area.
Technical Abstract: This is a review of research on vitamin C metabolism and functions in humans. It discusses the methodology and limitations of human nutrition studies in general, then summarizes the major studies of vitamin C metabolism in humans. Overall, these studies suggest that human vitamin C metabolism is complex. Vitamin C metabolism in healthy adults appears to depend on their intake of vitamin C and their body stores of vitamin C. Vitamin C metabolism appears to be influenced by sex, smoking, and possibly to some degree by age and stress. Furthermore, the amount of vitamin C calculated to meet estimated requirements or saturation depends on the test used and the tissue measured. Two recent attempts to derive recommendations for the dietary intake of vitamin C (the recommended dietary intake (RDI) and in situ kinetics) are summarized and evaluated. The review also summarizes and discussed profitable areas for future research, gaps in scientific information and presentation, and the controversy surrounding recommendations for dietary intake.