Blood Thinners: I'm On Coumadin - Do I Need A Special Diet Or A Coumadin Diet?

Why is it so important to be on a special diet if you take Coumadin (warfarin), which is a blood thinner?  It is because of the amount of vitamin K that you may have in your diet. 

What does vitamin K have to do with Coumadin?  Vitamin K changes the way that the drug Coumadin or warfarin affects your blood.  If you have an excess of vitamin K in your diet, you can decrease the effects of the anticoagulant (blood thinner).  Likewise, if you eat less of vitamin K, you can increase the effect of the medication. 

People generally get lost in the whole concept of ‘Coumadin diet’ because they think that they have to eat less or eat more of vitamin K to interact properly with Coumadin. In fact, that is not so. The most important fact of the ‘Coumadin diet’ is to make sure that your levels of vitamin K intake stay relatively THE SAME. The problem occurs when there are large fluctuations in the amounts of vitamin K foods or products that you ingest coupled with the Coumadin therapy.

Vitamin K is produced by the liver and it is used to make blood clotting proteins. Since Coumadin or warfarin is a blood thinner, you can readily see the possible effect that fluctuations in vitamin K levels could have – you could increase your ability to clot or decrease your ability to clot. Since people are on Coumadin because of the need to keep the blood’s clotting value lower, it is important to consider what foods could interfere with the medicine. It is not a matter of eating more of or less of vitamin-K-containing foods. Again, it is about maintaining a vitamin K intake without fluctuations.

Again – you do not have to avoid vitamin K containing foods! This could have the opposite effect on INR levels (the level used to measure the effects of Coumadin/warfarin). The safe level of a PT/INR is generally recommended to be 1.5 to 2.5 and if someone is on Coumadin or warfarin, they should be having their PT/INR monitored weekly - at least in the beginning. It is THAT important – if the level is too high, the risk of uncontrolled bleeding is extremely high – if too low, the risk of clot formation is extremely high.

The key is to eat a similar amount of foods that contain vitamin K every day. For instance, if you eat a spinach salad one day, you have probably enhanced your intake of vitamin K dramatically.

POINTS OF NOTE

• Do not make major changes to your diet without consulting a physician.
• If you are trying to lose weight and want to eat a lower fat diet or become a vegetarian, do not do this without consulting a physician if you are on Coumadin/warfarin because it can potentially change blood levels of vitamin K rapidly.
• So what foods are high in vitamin K? What level of vitamin K per day is safe to consume?
• Rule of thumb – green vegetables especially leafy vegetables and certain oils are high in vitamin K
• Most fruits, meats, dairy products and grains are low in vitamin K
• Myth – cranberry juice should be avoided – the evidence is saying that cranberry juice is okay to drink but as in all things, moderation and monitoring the amount that is consumed is key.
• The recommended daily allowance of vitamin K – 85-90 mcg per day for women 19-70+years and 120 mcg for men ages 19-70+ years
• Clotcare is an excellent source of information on levels of vitamin K as is the NutritionData website. QAS can also provide a vitamin K analysis on their PT/INR site. As in all things, if you have any questions about the diet that you should be on, consult your physician and be diligent in maintaining PT/INR checks. No one should be on Coumadin/warfarin without weekly blood checks.

Foods that are high in vitamin K(90-1150 mcg)

• Black tea (leaves) Brewed is low
• Green tea (leaves) Brewed is low
• Spinach noodles
• Kale
• Collards
• Spinach
• Turnip greens/beet greens/mustard greens
• Green leaf lettuce
• Brussels sprouts
• Broccoli
• Green onions
• Parsley
• Asparagus
• Endive
• Sauerkraut
• Okra
• Cabbage
• Rhubarb
• Plums dried or stewed
• Cowpeas or blackeye peas

These contain more than the recommended daily dose of vitamin K

Medium levels of vitamin K(30-60 mcg)

• Chinese cabbage
• Iceberg lettuce
• Romaine lettuce
• Celery
• Coleslaw
• Edible pea pods
• Savoy cabbage
• Blueberries FROZEN
• Pumpkin
• Green peas
• Tuna fish
• Carrot juice
• Spaghetti sauce
• Mung bean sprouts
• Cooked soybeans
• Kiwi

Low level vitamin K foods

• Tomato paste
• Mixed vegetables
• Blackberries
• Fresh blueberries
• Artichokes
• Grapes
• Cauliflower
• Carrots
• Miso
• Cucumber
• Snap beans
• Vegetable soup
• French fries
• Raspberries
• Salad dressings
• Pine nuts
• Fresh tomatoes
• Stuffing
• Potatoes
• Sodas
• Juices
• Alcoholic beverages – low BUT alcohol can lead to bleeding problems so should be avoided
• Condiments, sauces, pickles

Very low level vitamin K foods

• Nuts
• Lima beans
• Squash
• Mangoes
• Duck
• Beef stew
• Oatmeal
• Fruits
• Muffins
• Soy milk
• Peppers
• Soups
• Beans