Coumadin, also known as warfarin, is an anticoagulant drug used to prevent blood clots. Vitamin K is necessary for the clot formation process. Patients taking Coumadin should know that vitamin K and foods rich in the vitamin can affect how the drug works, according to MayoClinic.com. Patients should consult their healthcare provider about how to eat a healthy balanced diet while, at the same time, avoiding too much consumption of vitamin-K containing foods.
Balanced Diet
Patients taking Coumadin should eat a balanced diet that contains carbohydrates, protein, fat, minerals, salts and fiber, which provides enough energy and nutrition for optimal growth and development, according to MayoClinic.com. However, patients should be aware that certain foods high in vitamin K can make Coumadin less effective in preventing blood clots. It is important for patients to get consistent amounts of vitamin K daily from vegetables that are not high in vitamin K, such as corn, squash, carrots, onions, celery, cucumbers, pumpkin, tomatoes and peppers. Patients should avoid eating large amounts of foods rich in vitamin K, such as spinach, kale, brussels sprouts, mustard greens, parsley, green tea and collard greens.
Cranberries and Cranberry Products
Patients taking Coumadin should avoid eating cranberries, drinking cranberry juice and using cranberry herbal products, according to ClevelandClinic.com. Cranberry products interact with Coumadin and increase the effects of Coumadin on the body, leading to increased risks of bruising and bleeding.
Alcohol
Patients taking Coumadin should avoid consuming large amounts of alcohol as alcohol interferes with the effectiveness of Coumadin, according to ClevelandClinic.com. Alcohol also increases the risk of stomach bleeding. Signs of gastrointestinal bleeding include vomiting blood, dark-colored stool, coughing blood, weakness and dizziness upon standing.
Grapefruit and Grapefruit Juice
Patients taking Coumadin should avoid eating grapefruits and drinking grapefruit juice, according to ClevelandClinic.com. Grapefruit products increase the risk of bleeding when used with Coumadin and other blood thinners.
Herbal Supplements
Some herbal products may increase or decrease the effect of Coumadin in thinning blood, according to ClevelandClinic.com. It is important for patients to inform the healthcare provider of the herbal supplements they are taking as the Coumadin dose may need to be adjusted. Certain herbal supplements should not be taken prior to surgery in patients taking Coumadin. These herbs include garlic, ginger, ginseng, ginkgo biloba, fish oil, turmeric and St. Johns wort.
