Vitamin K supplementation improves stability of anticoagulation
Can vitamin K supplementation help achieve stable control of anticoagulation in adults taking warfarin?
Vitamin K supplementation can help achieve control of anticoagulation in adults with unexplained instability of response to warfarin. This may be a welcome relief to frustrated patients, clinicians, and staff. (LOE = 1b)
Sconce E, Avery P, Wynne H, Kamali F. Vitamin K supplementation can improve stability of anticoagulation for patients with unexplained variability in response to warfarin. Blood 2007;109(6):2419-23. [PMID:17110451]
Randomized controlled trial (double-blinded)
Anticoagulation that is difficult to control in adults taking warfarin may be due to an irregular intake of foods that contain vitamin K. These investigators identified 70 warfarin-treated adults with unstable anticoagulation, defined as having a standard deviation of INR values greater than 0.5 (indicating a wide swing in values) and at least 3 warfarin dose changes in the previous 6 months. Eligible patients randomly received vitamin K (150 ug daily) or matched placebo in a double-blind fashion (concealed allocation assignment). Individuals masked to treatment assignment assessed outcomes. Complete follow-up occurred for 97% of the patients at 6 months. Using intention-to-treat analysis, stable anticoagulation control occurred in significantly more patients taking vitamin K supplementation than in patients taking placebo (54% vs 21%; number needed to treat = 3; 95% CI, 2-10). Daily warfarin dose requirements also increased in significantly more patients in the vitamin K group than in patients in the placebo group (16% vs 1.5%, respectively). No adverse events occurred in either treatment group.
Barry, Henry, et al., editors. "Vitamin K Supplementation Improves Stability of Anticoagulation." EE+ POEM Archive, John Wiley & Sons, 2019. Evidence Central, evidence.unboundmedicine.com/evidence/view/infoPOEMs/426470/all/Vitamin_K_supplementation_improves_stability_of_anticoagulation.
Vitamin K supplementation improves stability of anticoagulation. In: Barry HH, Ebell MHM, Shaughnessy AFA, et al, eds. EE+ POEM Archive. John Wiley & Sons; 2019. https://evidence.unboundmedicine.com/evidence/view/infoPOEMs/426470/all/Vitamin_K_supplementation_improves_stability_of_anticoagulation. Accessed September 22, 2023.
Vitamin K supplementation improves stability of anticoagulation. (2019). In Barry, H., Ebell, M. H., Shaughnessy, A. F., & Slawson, D. C. (Eds.), EE+ POEM Archive. John Wiley & Sons. https://evidence.unboundmedicine.com/evidence/view/infoPOEMs/426470/all/Vitamin_K_supplementation_improves_stability_of_anticoagulation
Vitamin K Supplementation Improves Stability of Anticoagulation [Internet]. In: Barry HH, Ebell MHM, Shaughnessy AFA, Slawson DCD, editors. EE+ POEM Archive. John Wiley & Sons; 2019. [cited 2023 September 22]. Available from: https://evidence.unboundmedicine.com/evidence/view/infoPOEMs/426470/all/Vitamin_K_supplementation_improves_stability_of_anticoagulation.
* Article titles in AMA citation format should be in sentence-case
TY - ELEC T1 - Vitamin K supplementation improves stability of anticoagulation ID - 426470 ED - Barry,Henry, ED - Ebell,Mark H, ED - Shaughnessy,Allen F, ED - Slawson,David C, BT - EE+ POEM Archive UR - https://evidence.unboundmedicine.com/evidence/view/infoPOEMs/426470/all/Vitamin_K_supplementation_improves_stability_of_anticoagulation PB - John Wiley & Sons DB - Evidence Central DP - Unbound Medicine ER -