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Blood Coagul Fibrinolysis. 2000 Apr;11(3):309-11.

Severe acquired vitamin K deficiency: a hypothesis for rapid response to therapy.

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Department of Pathology, University of Vermont and Fletcher Allen Health Care, Burlington 05405, USA.


The potential mechanism underlying the rapid response to vitamin K replacement in acquired deficiency states is incompletely understood. To examine vitamin K metabolism, a 10-year-old boy with autoimmune enteropathy on oral vitamin K supplementation, who presented with profuse nosebleeds and calf tenderness, was evaluated. Laboratory analyses were consistent with severe vitamin K deficiency: vitamin K dependent protein (VKDP) levels < 5%, normal vitamin K epoxide level and depressed total prothrombin antigen (carboxylated and undercarboxyated forms). Intramuscular vitamin K (10 mg) was administered. Nine hours following therapy, VKDP levels corrected completely. Total prothrombin antigen increased indicating new prothrombin synthesis. However, the increase in the prothrombin-clotting assay far exceeded the increase in total prothrombin, supporting storage of undercarboxylated prothrombin in vitamin K deficiency states, with carboxylation and secretion after vitamin K replacement. Although this mechanism is known to occur in rodents, it has not been reported in humans. Our findings suggest a new potential mechanism of prothrombin metabolism in humans.

[Indexed for MEDLINE]

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