Vitamin K deficiency thus activate) certain enzymes involved in coagulation: Factors II, VII, IX, X, and protein C and protein S. Inability to activate the clotting cascade via these factors leads to the bleeding symptoms mentioned above. Notably, when one examines the lab values in Vitamin K deficiency [see below] the prothrombin time is elevated, but the partial thromboplastin time is normal or only mildly prolonged. This may seem counterintuitive given that the deficiency leads to decreased activity in factors of both the intrinsic pathway (F-IX) which is monitored by PTT, as well as the extrinsic pathway (F-VII) which is monitored by PT.
Vitamin B12 deficiency anemia antibodies for parietal cells; however, only 50% of all individuals in the general population with these antibodies have pernicious anemia. Forms of vitamin B deficiency other than PA must be considered in the differential diagnosis of megaloblastic anemia. For example, a B-deficient state which causes megaloblastic anemia and which may be mistaken for classical PA may be caused by infection with the tapeworm "Diphyllobothrium latum", possibly due to the parasite's competition with host for vitamin B. The classic test for PA, the Schilling test, is no longer widely used, as more efficient methods are available. This historic test consisted, in