Vitamin K Deficiency – Step 2 CK Exam

by / Tuesday, 22 June 2010 / Published in Internal Medicine

Vitamin K deficiencies are most commonly seen in critically ill patients who are NPO and on antibiotics.



  • A co-factor in the synthesis of factors 2,7,9, and 10
  • Also a co-factor for protein C and S in the liver
  • The best sources of vitamin K are leafy green veggies
  • Vitamin K is synthesized by intestinal bacterial flora


  1. Broad Spectrum Antibiotics – Suppression of the gut flora
  2. Patients on TP nutrition – Occurs unless vitamin K is added to nutrition
  3. Fat soluble vitamin malabsorption – In small bowel disease, irritable bowel syndromes, and obstructive jaundice
  4. Warfarin – A vitamin K antagonists which cause the production of inactive clotting factors


  • HEMORRHAGE – This may develop into serious, life-threatening bleeds
  • PT PROLONGATION – Initially the PT is prolonged (because factor 7 has the shortest half-life at 3-5hrs), and as the other factors diminish the PTT will be prolonged.


  • REPLACE VITAMIN K – The PT will normalize within a few days
  • FRESH FROZEN PLASMA – Should be transfused in a severe bleeding condition and when situation is an emergency

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