Some Effects of Topical Vitamin A upon Human Epidermis

In the past few years more and more interest has been focused on the action of vitamin A upon the skin. Earlier investigators noted the effect on human and animal epidermis following the oral administration of vitamin A. More recently the action of local applications of vitamin A has received increasing attention. However, as far as we have been able to discover, with the exception of one report by Reiss and Campbell,*until now systematic histologic studies of the local effects of vitamin A have been limited to observations on the epidermis of laboratory animals. Many matters concerning vitamin A and its effects upon the epidermis are still somewhat controversial; and a review of some of the findings and opinions expressed in the literature appears worth while at this point. Observations in Laboratory Animals Effects of Deficiency or Systemic Administration.—Moult demonstrated hyperkera