Vitamin K deficiency under enteral feeding: real or imagined threat

Patients receiving enteral feeding may develop vitamin K deficiency if the nutrition formula does not meet their daily vitamin K requirement. Vitamin K is essential for clotting factors II, VII, IX and X to be released in their functional form. Under vitamin K deficiency a coagulopathy may develop which is marked by prolongation of the prothrombin time (PT). There might be a need, unrecognized to-day, for monitoring the PT in patients receiving enteral feeding to unmask a latent coagulopathy. We assessed the prevalence of a prolonged PT in patients receiving enteral feeding for 3 months of more with one or a combination of the enteral formulas Osmolite®, Jevity®, Easymilk®. Twenty-three residents in long-term hospital care received solely enteral feeding for an average of 37 months, SD 21 months. The median daily vitamin K supplied by enteral feeding was 96.8 mcg (average 103.3 mcg, SD 28.8); this does not satisfy the 150 mcg of vitamin K required by the Food and Drug Administration. In 21 patients the PT-INR was 1-1.2 (normal). The PT was prolonged in two patients. In one of the latter, prolongation of PT-INR was not confirmed two days later. In the second case, the patient having repeatedly a PT-INR 1.4 (and a normal APTT), administration of vitamin K did not correct the PT. In conclusion, long-term vitamin K-deficient nutrition did not affect the vitamin K-dependent coagulation. This data may argue against the supposed need to monitor the PT in patients receiving long-term enteral nutrition.