Q. I enjoyed your Special Report on food-drug and supplement-drug interactions (May), which states that glucosamine should not be taken with warfarin. Can you explain why?

A. Our source for this information was the National Library of Medicines MedlinePlus, which explains: Warfarin (Coumadin) is used to slow blood clotting. There are several reports showing that taking glucosamine hydrochloride with or without chondroitin increases the effect of warfarin (Coumadin) on blood clotting. This can cause bruising and bleeding that can be serious. Dont take glucosamine hydrochloride if you are taking warfarin (Coumadin).