title: Patients with unstable control have a poorer dietary intake of vitamin K compared to patients with stable control of anticoagulation.
abstract: Evidence suggests that alterations in the dietary intake of vitamin K can affect anticoagulation response to warfarin. It is possible that a low and erratic intake of dietary vitamin K is at least partly responsible for the variable response to warfarin in patients with unstable control of anticoagulation. Twenty-six patients with unstable and twenty-six with stable control of anticoagulation completed dietary records of all foods and drinks consumed on a daily basis for two consecutive weeks. The mean daily intake of vitamin K in unstable patients was considerably lower than that for stable patients during the study period (29+/-17 microg v . 76+/-40 microg). The logarithm of vitamin K intake was consistently and significantly lower in the unstable patients than the stable patients over the two week period (5.9+/-0.4 microg v. 6.9+/-0.5 microg; p<0.001; 95% CI: 0.7-1.2). Changes in vitamin K intake between weeks 1 and 2 of the study were negatively correlated with changes in International Normalised Ratio (INR) amongst the unstable patients, however this failed to reach significance (r=-0.25; p=0.22). Daily supplementation with oral vitamin K in unstable patients could lead to a more stable anticoagulation response to warfarin.
authors.affiliation: School of Clinical and Laboratory Sciences, University of Newcastle upon Tyne, UK.
authors.forename: Elizabeth
authors.initials: E
authors.lastname: Sconce
authors.forename: Tayyaba
authors.initials: T
authors.lastname: Khan
authors.forename: Jennifer
authors.initials: J
authors.lastname: Mason
authors.forename: Faye
authors.initials: F
authors.lastname: Noble
authors.forename: Hilary
authors.initials: H
authors.lastname: Wynne
authors.forename: Farhad
authors.initials: F
authors.lastname: Kamali
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000925:Anticoagulants / Q000494:pharmacology*; D001281:Atrial Fibrillation / Q000188:drug therapy*; D001777:Blood Coagulation; D004032:Diet; D004347:Drug Interactions; D005260:Female; D006801:Humans; D019934:International Normalized Ratio; D008297:Male; D008875:Middle Aged; D009752:Nutritional Status; D013997:Time Factors; D016896:Treatment Outcome; D020246:Venous Thrombosis / Q000188:drug therapy*; D014812:Vitamin K / Q000494:pharmacology*; D014859:Warfarin / Q000494:pharmacology
chemical_list: D000925:Anticoagulants; D014812:Vitamin K; D014859:Warfarin