Vitamin A and the developing embryo

Abstract

Soon after, in the 1930s, similar dietary deprivation studies were performed with a view to asking what happens to the embryo when vitamin A is removed. In fact vitamin deficiencies, and most dramatically deficiencies of vitamin A, were the first dietary means of producing congenital malformations of the embryo. Most of these experiments were done with farm animals and the first report of this type of experiment was that a litter of pigs were born with no eyes at all.2Subsequently it was shown that a wide range of embryonic defects were apparent in the vitamin A deficient embryos of sheep, cattle, rabbits, rats, and humans.3 These defects include the central nervous system (hydrocephalus, spina bifida), eyes (anophthalmia, microphthalmia), face (harelip, cleft palate), dentition, ear (accessory ears, otosclerosis) limb, urinogenital system (cryptorchidism, ectopic ovaries, pseudohermaphrotisism, renal defects), skin (subcutaneous cysts), lungs (hypoplasia), and heart (incomplete ventricular septation, spongy myocardium, aortic arch defects, aorticopulmonary septal defects, valvulus communis). Clearly, the developing embryo crucially requires vitamin A for the proper development of a whole range of its organ systems.