More than 250 years has elapsed since the first case of hemorrhagic disease of the newborn was recorded in medical literature and a specific form of treatment was discovered. The events leading up to this discovery form a fascinating chapter in the history of medicine and have recently been reviewed in detail elsewhere.1While excellent contributions on the nature of the disease had been made by Lespinasse and Fischer,2Schloss and Commiskey,3Whipple,4Løvegren,5Rodda,6Gelston7and others, the fundamental observation that served as the impetus for the solution of the exact pathogenesis and treatment of the disease was the investigative work of Henrik Dam, of Denmark.8Dam, in the course of biochemical investigations on sterol metabolism in chicks, found that when they were fed a fat-free diet fatal hemorrhage resulted. Further study showed that the hemorrhagic manifestations were associated with low