RESUMEN
Newborns are susceptible to postnatal Vitamin K deficiencies from limited placental transfer, gastrointestinal absorption, and bioavailability in breast milk and formula preparations. For over 50 years, the American Academy of Pediatrics has recommended prophylactic vitamin K to prevent hemorrhagic disease in newborns. Yet, public skepticism contributes to increasing refusal rates. We present three cases of vitamin K-dependent bleeding following parental refusal of postnatal prophylaxis. Two patients experienced intracranial hemorrhage with resultant neurological devastation and mortality, respectively. The third child presented with symptomatic hematuria. Perinatal providers must partner with families and advocate vitamin K prophylaxis to limit unnecessary morbidity and mortality.