What do I need to know about diet interactions with warfarin?
Because warfarin exerts its effect by reducing the ability of your liver to use vitamin K to make normally functioning blood clotting proteins, any dietary change that alters your vitamin K intake can alter your response to warfarin. Such dietary changes may increase your risk of blood clot formation or bleeding; either of which may result in serious harm or even death. Therefore, it is very important that you keep your anticoagulation clinician up-to-date on any planned changes in your diet (including vitamins, nutrition supplements, herbal preparations, etc.). This does NOT mean, however, that you should avoid vitamin K containing foods. In fact, this is a popular misconception among both patients and some clinicians. Reducing the amount of vitamin K in your diet may both cause your INR to increase to a dangerous level and make the INR more difficult to control. The most important dietary consideration is consistency. This does not mean that you have to eat the same thing every day.
