Ask the doctor: Do people on warfarin need to avoid vitamin supplements that contain vitamin K?
Ask the doctor
Do people on warfarin need to avoid vitamin supplements that contain vitamin K?
Q. In your January issue you mentioned Centrum Cardio, a new multivitamin supplement that supposedly lowers cholesterol. Taking two tablets a day, as recommended, would deliver 25 micrograms of vitamin K. Is it wise to recommend this product for someone taking warfarin or other anticoagulants?
A. You raise an interesting point about vitamin K and its interaction with warfarin (Coumadin). This widely used drug prevents the formation of blood clots in the bloodstream by interfering with the way vitamin K helps produce clotting proteins. The more vitamin K in circulation, the more warfarin is needed to achieve a particular anti-clotting level.