<prompt> A three day-old term infant borne at home, breast-fed exclusively, presented with lethargy, bulging fontanel, and bright red blood from rectum. What is the most likely etiology of his disease?Fluoride deficiency.Ca deficiency.Vitamin K deficiency.Iron Deficiency  <response>: Vit K deficiency is associated with hemorrhagic disease of newborn which has manifested in this baby as Intracranial hemorrhage bulging fontanel and GI bleed blood per rectum. Moreover home delivery Vit K may not have been given at bih and exclusive breast feeding Vit K is deficient in breast milk clearly point to Vit K deficiency as etiology. 