Studies which have been previously published by our group suggests that oral vitamin K effectively reduces the INR value. However, despite their rigour, and their publication in high-impact journals, our studies have not yet influenced clinical practice. A recent US survey confirmed that most clinicians faced with an excessively anticoagulated, non-bleeding patient would simply withhold warfarin and not give oral vitamin K (18). The lack of use of vitamin K is attributable to at least four factors; first, no study has unequivocally shown that oral vitamin K reduces the risk of hemorrhage. Although our first randomized trial (13) did find less bleeding in patients who received vitamin K, the bleeding in the placebo group occurred more than one week after randomization, making it possible that this observation was attributable to the play of chance. Second, there is concern that, irrespective of its route of administration, vitamin K may place patients at risk of thrombosis by "over-correcting" the INR. Although our two randomized trials showed no evidence that low dose vitamin K causes either warfarin resistance or thrombosis, at least one other publication has suggested this might occur (19). Third, the "passive" strategy of merely withholding warfarin is simple, inexpensive and easily applied. Finally, access to a convenient form of vitamin K is a major barrier as there is no convenient and easily administered form of oral vitamin K in many jurisdictions.