If you are taking an anticoagulant or a blood thinner, like Warfarin (Coumadin), then it is important to keep your PT/INR (Prothrombin Time and International Normalized Ratio) levels stable. PT/INR measure factors of blood coagulation.
In order to maintain stable PT/INR levels you should not eat more than 1 serving of a high vitamin K food, and no more than 3 servings of a food with moderate amounts of vitamin K. What is important is that your intake of vitamin K stays consistent. Having a cheat day where you eat a large amount of vitamin K, like a spinach salad, could be extremely harmful.
This is a guide of what foods you can eat and in what amounts. Exact amounts depend on your dosage of Warfarin. Listed below are foods low in vitamin K presented by food group with sample serving sizes and amounts of vitamin K. For more ideas, use the nutrient ranking tool to sort by food group and serving size.
A low INR means you have increased risk of clotting
A high INR means you have an increased risk of bleeding
Warfarin increases INR, Vitamin K decreases it
Most doctors aim to keep INR around 2-3, but can range to 2.5-3.5 for heart valves or other extreme cases
When a doctor prescribes Warfarin, they are trying to balance it with how much vitamin K you eat
Regularly check your PT/INR levels
Take the same amount of Warfarin at the same time each day
Keep your intake of vitamin K consistent from day to day
Eat no more than 1 serving of food that contains 200%-600% DV of vitamin K
Eat no more than 3 servings of food that contains 60-200% DV of vitamin K
Eliminate alcohol if you can, or limit yourself to no more than 3 drinks a day
Take no more than 800IU of vitamin E supplements
Avoid cranberries and cranberry juice as they can raise INR and risk of bleeding
Limit or avoid grapefruit and grapefruit juice
Avoid drinking green tea as it antagonizes Warfarin and lowers INR
Work with your doctor when taking CoQ10 as it can hamper the effectiveness of Warfarin
Many natural supplements affect PT/INR levels, so it is best to avoid them unless your doctor advises otherwise. The following supplements definitely affect PT/INR levels: arnica, bilberry, butchers broom, cat's claw, dong quai, feverfew, forskolin, garlic, ginger, gingko, horse chestnut, insositol hexaphosphate, licorice, melilot(sweet clover), pau d'arco, red clover, St. John's wort, sweet woodruff, turmeric, willow bark, and wheat grass.
List of Vitamin K foods to limit to 1 serving per day (200%-660% DV)
Vitamin K Content
Boiled Mustard Greens
Boiled Collard Greens
Boiled Turnip Greens
Boiled Swiss Chard
List of Vitamin K foods to limit to 3 serving per day (60%-200% DV)
Avoid grapefruit and cranberries See the full list of fruits low in vitamin K. Low vitamin K does not necessarily guarantee safe administration of Warfarin (Coumadin).
Grains/Starches Low in Vitamin K
All grain products are low in vitamin K. Here are some examples:
Vitamin K Content
0μg (0% DV)
0.4μg (1% DV)
0.2μg (0% DV)
Cornmeal (White or Yellow)
0.4μg (0% DV)
0.9μg (1% DV)
1.3μg (2% DV)
0μg (0% DV)
Whole Wheat Bread
0μg (0% DV)
3.2μg (4% DV)
0.5μg (1% DV)
0.0μg (0% DV)
See the full list of grains low in vitamin K. Low vitamin K does not necessarily guarantee safe administration of Warfarin (Coumadin).
Other Food Groups
All meats are low in vitamin K with the exception of some canned fish packed in oil, and abalone.All Dairy and Egg Products are low in Vitamin K. Besides black-eyed peas, soybeans, soy products, and green beans, all beans and legumes are low in vitamin K. If you are into juicing, here are some low vitamin K juice recipes.
Avoid making any big changes to your diet. If you try any new food, try it in small quantities and monitor your PT/INR
Even though a food is low in vitamin K it does not mean that it will not interact with Warfarin (Coumadin).This article is intended as a general guide for foods low in vitamin K and is for information purposes only.As stated above, try new foods with caution and consult health care providers or literature before trying new foods.