<prompt> Which is likely to be increased in vitamin K deficiency: March 2004PTTPTPlatelet countFibrinogen time  <response>: Ans. B i.e. PT Prothrombin time PT PT and its derived measures of prothrombin ratio PR and international normalized ratio INR are measures of the extrinsic pathway of coagulation. This test is also called ProTime INR and PT INR. They are used to determine the clotting tendency of blood, in the measure of warfarin dosage, liver damage, and vitamin K status. PT measures factors I fibrinogen, II thrombin, V, VII, and X. It is used in conjunction with the activated paial thromboplastin time aPTT which measures the intrinsic pathway. 