The transport of vitamin C and effects of disease

Abstract

It has been known for a number of years that high concentrations of vitamin C (ascorbic acid + dehydroascorbic acid) occur in some cells, but it is only recently that we have begun to discover how high the levels are and also that the vitamin seems to be secreted onto epithelial surfaces (Table 1). If we assume that such concentrations and secretions are needed for the appropriate biological activity of the vitamin, it follows that transport of vitamin C will be required in order to sustain normal metabolic functions. Further, if transport is central to the metabolism of vitamin C, any defect in the process could lead to the development of disease. The study of transport mechanisms is, therefore, important in our understanding of vitamin C metabolism and this review will examine our present knowledge in this area and speculate on diseases that may impair these processes.