Evidence against Vitamin K Deficiency in Normal Neonates

Abstract
Summary: Umbilical cord plasmas from 24 normal full-term neonates were studied. We confirmed the prolonged prothrombin time and low levels of Vitamin K dependent clotting factors previously described (1), but using a number of recently developed immunological and coagulation techniques we could find no evidence of vitamin K deficiency. We conclude that the decreased levels of vitamin K dependent clotting factors of normal neonates are the result of decreased synthesis by the immature liver and that it is questionable whether vitamin K prophylaxis is necessary for these infants.