Retro-Retinoids: Metabolism and Action

In a classic histological study published in 1925 Wolbach and Howe described the widespread pathology associated with vitamin A deficiency in rats. The reported abnormalities included stunted growth, blindness, keratinization of the epithelial linings of the respiratory and alimentary tracts, defective development of testis and atrophy of the central and peripheral lymphoid organs. Subsequent studies with vitamin A deficient animals have confirmed these findings and have established a critical role for retinol in the normal development and maintenance of most tissues.