ABSTRACT
It will be evident from the following discussion that most of our knowledge about plasma vitamin turnover and homeostasis results from work in animal models, especially the rat However, new data from a small-scale human kinetic study of retinol turnover are presented here and they indicate that there are many similarities between the two species. The subsequent pages will emphasize that many significant and interesting questions remain to be answered about the turnover, utilization, and regulation of plasma retinol in humans and animal models.
