Effect of Vitamin K on the Clotting Time of the Prothrombin and the Blood

PART 1 The desirability of finding some agent which might materially lessen the incidence of cerebral accident and unnatural bleeding in the neonatal period prompted this study of the effect of vitamin K concentrate on the prothrombin-clotting time and the clotting time of the blood of the newly born. Before presenting our results it seems advisable to review briefly the history of vitamin K concentrate. During work on sterol metabolism in the chick, Dam¹in 1929 observed that diets deficient in certain respects gave rise to a disease which closely resembled scurvy. In this disease spontaneous bleeding occurred in the affected animals, clotting time was markedly prolonged and the plasma prothrombin was reduced to extremely low levels. Later he and his co-workers²suggested that this condition, which failed to respond to ascorbic acid administered either orally or subcutaneously, was a deficiency disease brought about by exclusion from the