Coumadin – Food/Nutrient Interaction

Coumadin – Food/Nutrient Interaction

With millions of Americans taking Coumadin (Warfarin) for high blood pressure, I thought this medication might be a good one to highlight. When you take Coumadin it interferes with the formation of a substance called prothrombin in the liver (this is why most doctors will have you take a prothrombin time test before giving you a prescription for Coumadin). Vitamin K is a naturally-occurring substance that is in foods we eat every day. Vitamin K makes blood more likely to clot, while Coumadin interferes with blood clotting.

Recommendations from nearly all the dietitians I have worked with are to not avoid eating foods high in vitamin K but to consume a consistent amount of vitamin K each day. For example, eat a healthy serving of greens often, but avoid eating a plateful of greens one day and no greens the rest of the week.

Foods high in vitamin K include kale, Swiss chard, collard greens, spinach, Brussels sprouts, watercress, endive, raw scallions, broccoli, coleslaw with dressing, cabbage, and asparagus. Ask your doctor or a dietitian if you have more questions about Coumadin and vitamin K.