Vitamin C is absorbed rapidly from the food and in a manner similar to that of glucose (Sauberlich, 1975). In humans, the vitamin is absorbed through the mucous membranes of the mouth, the stomach, and the upper part of the small intestine, and hence passes into the bloodstream (Spencer et al., 1963; Wilson, 1974). ‘The mechanism of absorption consists of a passive diffusion of the vitamin through the lipoid cell membranes and of an active partition of the vitamin into the cells lining the lumen of the alimentary canal’ (Wilson, 1973a).