Patients with unstable control have a poorer dietary intake of vitamin K compared to patients with stable control of anticoagulation

Summary

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±17μg v. 76±40µg). 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±0.4µg v. 6.9±0.5µg; 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.

Keywords

Warfarin - anticoagulation - diet - vitamin K

• References

• 1 Stroke Prevention in Atrial Fibrillation Investigators. Adjusted-dose warfarin versus low-intensity, fixed dose warfarin plus aspirin for high risk patients with atrial fibrillation: Stroke prevention in atrial fibrillation III randomised clinical trial. Lancet 1996; 348: 633-8.
• 2 Poller L, Shiach CR, Mac Callum PK. et al. Multicentre randomised study of computerised anticoagulant dosage. Lancet 1998; 352: 1505-9.
• 3 Stroke Prevention in Atrial Fibrillation Investigators. Bleeding during antithrombotic therapy in patients with atrial fibrillation. Arch Intern Med 1996; 156: 409-16.
• 4 Cannegieter SC, Rosendaal FR, Wintzen AR. et al. Optimal oral anticoagulant therapy in patients with mechanical heart valves. N Engl J Med 1995; 333: 11-17.
• 5 Shearer MJ, Vitamin K.. Lancet. 1995; 345: 229-34.
• 6 Choonara IA, Malia RG, Haynes BP. et al. The relationship between inhibition of vitamin K₁ 2, 3-epoxide reductase and reduction of clotting factor activity with warfarin. Br J Clin Pharmacol 1988; 25: 1-7.
• 7 Bolton’Smith C, Price RJG, Fenton ST. et al. Compilation of a provisional UK database for the phylloquinone (vitamin K₁) content of foods. Br J Nutr 2000; 83: 389-99.
• 8 Booth SL, O’Brien-Morse ME, Dallal GE. et al. Response of vitamin K status to different intakes and sources of phylloquinone-rich foods: comparison of younger and older adults. Am J Clin Nutr 1999; 70: 369-77.
• 9 Khan T, Wynne HA, Wood P. et al. Dietary vitamin K influences intra-individual variability in anticoagulant response towarfarin. Br J Haematol 2004; 124: 348-54.
• 10 Marr JW. Individual weighed dietary surveys. Nutrition 1965; 19: 18-24.
• 11 Bingham SA, Gill C, Welch A. et al. Comparison of dietary assessment methods in nutritional epidemiology: weighed records v. 24 h recalls, food frequency questionnaires and estimated diet records. Br J Nutr 1994; 72: 619-43.
• 12 Ministry of Agriculture Fisheries and Food. Food portion sizes. 2^nd ed: London H.M. Stationary Office; 1993.
• 13 McCance RA, Widowson EM. The composition of Foods: Royal Society of Chemistry and Ministry of Agriculture Fisheries and Foods. 1991
• 14 Chow WH, Chow TC, Tse TM. et al. Anticoagulation stability with life-threatening complication after dietary modification. Postgrad Med J 1990; 66: 855-7.
• 15 O’Reilly RA, Rytand DA. Resistance to warfarin due to unrecognised vitamin K supplementation. N Engl J Med 1980; 303: 160-1.
• 16 Karlson B, Leijd B, Hellstrom K. et al. On the influence of vitamin K-rich vegetables and wine on the effectiveness of warfarin treatment. Acta Med Scand 1986; 220: 347-50.
• 17 Lubetsky A, Dekel-Stern E, Chetrit A. et al. Vitamin K intake and sensitivity to warfarin consuming regular diets. Thromb Haemost 1999; 81: 396-9.
• 18 Pederson FM, Hamberg O, Hess K. et al. The effect of dietary vitamin K on warfarin-induced anticoagulation. J Int Med 1991; 229: 517-20.
• 19 Sorano GG, Biondi G, Conti M. et al. Controlled vitamin K intake in chronic oral anticoagulation: a clinical proposal. Haemostasis 1993; 23: 77-82.
• 20 Franco V, Polanczyk CA, Clausell N. et al. Role of dietary vitamin K intake in chronic oral anticoagulation: prospective evidence from observational and randomized protocols. Am J Med 2004; 116: 651-6.
• 21 Schurgers LJ, Shearer MJ, Hamulyak K. et al. Effect of vitamin K intake on the stability of oral anticoagulant treatment: dose-response relationships in healthy subjects. Blood 2004; 104: 2682-9.
• 22 Thane CW, Paul AA, Bates CJ. et al. Intake and sources of phylloquinone (vitamin K 1 ): variation with socio-demographic and lifestyle factors in a national sample of British elderly people. Br J Nutr 2002; 87: 605-13.
• 23 Booth SL, Centurelli MA. Vitamin K: a practical guide to the dietary management of patients on warfarin. Nutr Rev 1999; 57: 288-96.
• 24 Cushman M, Booth SL, Possidente CJ. et al. The association of vitamin K status with warfarin sensitivity at the onset of treatment. Br J Haematol 2001; 112: 572-7.
• 25 Uematsu T, Nagashima S, Niwa M. et al. The effect of dietary fat content on oral bioavailability of vitamin K. J Pharm Sci 1996; 85: 1012-6.
• 26 Booth SL, Charnley JM, Sadowski JA. et al. Dietary vitamin K and stability of oral anticoagulation: proposal of a diet with constant vitamin K content. Thromb Haemost 1997; 77: 504-9.