Effects of dietary vitamin K on the stability of warfarin anticoagulation therapy / 中国临床药理学与治疗学

ABSTRACT

Change in dietary vitamin K intake is one of the main causes of abnormal fluctuations in international standardized ratio (INR) of patients on warfarin therapy. Advice from clinicians on how to manage vitamin K intake for patients has been vague. In the past, patients were often told to restrict or avoid vitamin K-rich foods including leafy greens during anticoagulation therapy, which could lead to lower vitamin K intake. Evidence-based studies in recent years have found that instability of warfarin therapy is associated with low intake of vitamin K. A stable and relatively higher daily intake of vitamin K (>100 μg/d) can reduce unexplained intra-individual variability in response to warfarin, and thus reduce abnormal fluctuations in INR and improve the stability of anticoagulation therapy.