title: Unsuspected source of vitamin K in patients treated with anticoagulants: a case report.
abstract: The administration of warfarin requires careful attention. The concurrent intake of drugs can either enhance or compete with its anticoagulant effect. Less frequently encountered are the effects from vitamin K added to food, intake of foods with naturally occurring high levels of vitamin K and diets deficient in vitamin K. We report a case in which loss of anticoagulant control was caused by a dietary supplement taken during a weight reducing diet by a patient who was receiving warfarin following a pulmonary embolus. A review of the literature reveals several similar cases. Amounts of vitamin K in food supplements and in foods with large amounts of naturally occurring vitamin K are tabulated along with suggestions for surveillance of patients taking anticoagulants.
authors.affiliation: Department of Family Medicine, Central Emek Hospital, Afula, Israel.
authors.forename: B
authors.initials: B
authors.lastname: Oren
authors.forename: P
authors.initials: P
authors.lastname: Shvartzman
mesh_terms: D000328:Adult; D005260:Female; D005527:Food, Fortified / Q000009:adverse effects*; D006801:Humans; D011655:Pulmonary Embolism / Q000188:drug therapy; D014812:Vitamin K / Q000009:adverse effects*; D014859:Warfarin / Q000008:administration & dosage / Q000494:pharmacology* / Q000627:therapeutic use
chemical_list: D014812:Vitamin K; D014859:Warfarin