To Take or Not to Take: A Case of Cholestyramine Induced Vitamin K Deficiency.

Cholestyramine resin combines with bile acids preventing their reabsorption from the small bowel, leading to a reduction in the absorption of fat-soluble vitamins A, D, E, and K. While rarely clinically significant, in some cases this can lead to vitamin K related coagulopathy. We present a case of a 57-year-old female with a profound vitamin K deficiency refractory to concomitant oral vitamin K supplementation in the setting of ongoing cholestyramine administration.