Coumadin® and Warfarin Diet Interactions
Some foods and other items you consume can change the way your Warfarin works. These include:
Foods that have Vitamin K
Some herbals and over-the-counter products
Vitamin K is common to many foods. It is very common in green leafy vegetables. Large amounts of
foods high in Vitamin K can reduce the effects of Warfarin or Coumadin®.
If you eat foods that are high in Vitamin K, it is vital to eat the same amounts of these foods each
week. Keep a log of how many servings and how often you eat foods high in vitamin K. This will help
you make sure you are eating the same amounts each week.
Foods high in Vitamin K:
Turnip and Mustard greens Watercress
Collards Green leaf lettuce
Swiss chard Endive lettuce
Parsley (okay as a garnish) Romaine lettuce
Brussels sprouts Soy Beans and Edamame
Other vegetables, fruits, cereals, dairy products, eggs, and meat contain smaller amounts of Vitamin K.
Remember: Eat the same amounts of foods high in Vitamin K each week.
Note: One serving of a high Vitamin K food = ½ cup cooked or 1 cup raw.
Herbals and Over the Counter (OTC) Products
Talk with your doctor or pharmacist if you take any of these herbals or over-the-counter products. Also
talk to them before starting or stopping any of these products:
Increases Bleeding Risks Increase Clot Risk
Feverfew St. John’s Wort
Garlic (capsules) Coenzyme Q10
Ginger (capsules) Green tea
Omega-3 fatty acids
Multi-Vitamins likely contain Vitamin K and Vitamin E. If you do take a multi-vitamin, take your
dose every day. If you are not consistent with taking your multi-vitamin, you may reduce how well
your Warfarin works. Talk with your doctor or pharmacist before starting or stopping any multi-
Nutritional shakes may have high amounts of vitamin K per serving. If you will be starting one of
these products tell your warfarin manager. These drinks have vitamin K. This is not a complete list.
Carnation Breakfast Essentials® Slim Fast®
Ensure® Kellogg’s Special K Protein Shake ®
Drinking more than 2 drinks per day every day or binge drinking can greatly increase your risk for
bleeding. Limit alcohol to no more than 1 drink per day, or no more than 1-2 drinks on a special
What equals 1 drink?
Light Beer = 12 fluid ounces or 1.5 cups
Wine = 5 fluid ounces or ½ cup
Hard Liquor = 1.5 fluid ounce or 1 shot
What is the most important thing you learned from this handout?
What changes will you make in your diet/lifestyle, based on what you learned today?
If you are a UW Health patient and have more questions please contact UW Health at one of the phone
numbers listed below. You can also visit our website at www.uwhealth.org/nutrition.
Nutrition clinics for UW Hospital and Clinics (UWHC) and American Family Children’s
Hospital (AFCH) can be reached at: (608) 890-5500.
Nutrition clinics for UW Medical Foundation (UWMF) can be reached at: (608) 287-2770.
Your health care team may have given you this information as part of your care. If so, please use it and call if you have any
questions. If this information was not given to you as part of your care, please check with your doctor. This is not medical
advice. This is not to be used for diagnosis or treatment of any medical condition. Because each person’s health needs are
different, you should talk with your doctor or others on your health care team when using this information. If you have an
emergency, please call 911. Copyright © 3/2016 University of Wisconsin Hospitals and Clinics Authority. All rights reserved.
Produced by the Clinical Nutrition Services Department and the Department of Nursing. HF#322