Introduction Disruption of all vitamin K-dependent factors II, VII, IX, X, protein C, protein S See Vitamin topic Deficiency most commonly seen in newborns lack gut colonization by bacteria that produce vitamin K newborns are given IM vitamin K shot at birth for prophylaxis malabsorptive conditions long-term antibiotic therapy kills gut bacteria that produce vitamin K Presentation Symptoms hemarthroses intramuscular bleeding GI bleeding excessive bleeding in response to minor trauma Evaluation Labs ↑ PTT, PT normal bleeding time Treatment Administer vitamin K