Numerous risk factors for instability of oral anticoagulation have been identified, including variability in vitamin K intake. However, few studies have directly tested the feasibility of manipulating dietary vitamin K to achieve stable oral anticoagulation. Recent findings from a randomized clinical trial suggest that dietary vitamin K manipulation is a viable option for managing stability of oral anticoagulant therapy. The approach appears to be effective for those patients who are under-anticoagulated and consume a small number of vitamin K-rich food sources. While an encouraging option for management of warfarin therapy, longer-term studies in different patient populations are required.