Coumadin, also known as warfarin, is a blood thinner that some people take to decrease their risk for heart attacks, strokes and blood clots. While taking Coumadin, you need to watch your diet as some foods, beverages and supplements can interact with this medication, interfering with its function and making it less effective.
Vitamin K-Rich Foods
Since vitamin K helps increase blood clotting, you need to keep your vitamin K intake consistent while you are on Coumadin. You should consume only one serving per day of foods that are very high in vitamin K and provide over 200 percent of the daily value for vitamin K. Examples include 1/2 cup of cooked green leafy vegetables or 1/4 cup of parsley. Limit your intake of foods providing 60 percent or more of the daily value for vitamin K, such as 1/2 cup cooked Brussels sprouts or 1 cup of broccoli or raw green leafy vegetables, to 3 servings per day, according to the National Institutes of Health.
Other Foods to Limit
Cranberry juice and alcohol can both increase the effectiveness of Coumadin, so you should avoid these beverages or consume them only in very small amounts. Alcohol may also make it more likely that you will experience side effects from taking Coumadin.
Supplements
Certain supplements may also interact with Coumadin, either increasing or decreasing its effectiveness. Avoid supplements containing cranberry, as well as those containing red clover, licorice, horse chestnut, feverfew, dong quai, sweet clover, sweet woodruff, tonka beans, vitamin E, ginkgo, ginger, garlic, St. John's wort, turmeric, wheat grass, willow bark, bilberry, ginseng, coenzyme Q10, bromelains and arnica. Let your doctor know about any supplements you are taking, and ask before taking any new supplements.
Considerations
While you are on Coumadin, you shouldn't change your diet without letting your doctor know, and don't try to lose weight. These types of changes can affect the dosage of Coumadin needed to be effective. Coumadin may also interact with certain medications, including some antibiotics.
References
- MayoClinic.com; Warfarin Diet: What Foods Should I Avoid?; Sheldon G. Sheps, M.D.; May 13, 2010
- Agency for Healthcare Research and Quality; Blood Thinner Pills: Your Guide to Using Them Safely; August 2010
- Drugs.com; Coumadin; Dec. 21, 2010
- National Institutes of Health; Coumadin and Vitamin K; 2003
