Foods Low in Vitamin K for a Warfarin (Coumadin) Diet

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Written by Daisy Whitbread, BSc (Hons) MSc DipION
Foods Low in Vitamin K for a Warfarin (Coumadin) Diet

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 for 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 to which foods you can eat and in what amounts. Exact amounts will 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.

General points when taking Warfarin (Coumadin)

  • 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 it can go up to 2.5-3.5 for people with heart valve issues 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 herbs, roots, berries, and 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
    • Butcher's Broom
    • Cat's Claw
    • Dong Quai
    • Feverfew
    • Forskolin
    • Garlic
    • Ginger
    • Gingko
    • Goji Berries
    • Horse Chestnut
    • Insositol Hexaphosphate
    • Licorice
    • Melilot (Sweet Clover)
    • Pau D'arco
    • Red Clover
    • St. John's Wort
    • Sweet Woodruff
    • Turmeric
    • Willow Bark
    • Wheat Grass

List of Vitamin K foods to limit to 1 serving per day (200%-450% DV)

FoodServing SizeVitamin K Content
Boiled Kale1/2 cup(442% DV)
Boiled Spinach1/2 cup(370% DV)
Boiled Mustard Greens1/2 cup(346% DV)
Boiled Collard Greens1/2 cup(332% DV)
Boiled Turnip Greens1/2 cup(220% DV)
Boiled Swiss Chard1/2 cup(239% DV)
Raw Parsley1/4 cup(205% DV)

List of Vitamin K foods to limit to 3 serving per day (60%-100% DV)

FoodServing SizeVitamin K Content
Raw Spinach1 cup(121% DV)
Raw Turnip Greens1 cup(115% DV)
Raw Endive1 cup(96% DV)
Boiled Brussels Sprouts1/2 cup(91% DV)
Raw Broccoli1 cup(77% DV)
Raw Romaine Lettuce1 cup(40% DV)

Foods Low in Vitamin K to eat on a Warfarin (Coumadin) Diet

Vegetables Low in Vitamin K

FoodServing SizeVitamin K Content
Turnips (Raw or Cooked)1 cup0.1μg (0% DV)
Beets (Raw or Cooked)1 cup0.3μg (0% DV)
Sweet Corn (Raw or Canned)1 cup0.5μg (1% DV)
Onions (Raw or Cooked)1 medium (331g)1μg (1% DV)
Rutabagas (Raw or Cooked)1 cup0.5μg (1% DV)
Pumpkin (Cooked)1 cup2μg (2% DV)
Winter Squash, Butternut/Spaghetti (Cooked)1 cup2μg (2% DV)
Summer Squash (Cooked)1 cup3μg (3% DV)
Potatoes (Cooked)1 cup3μg (3% DV)
Sweet Potatoes (Cooked)1 cup7μg (6% DV)
Eggplants (Cooked)1 cup3μg (4% DV)
Bamboo shoots (Raw or Canned)1 cup0μg (0% DV)
Portabella Mushrooms (Raw or Cooked)1 cup0μg (0% DV)
White Mushrooms (Raw or Cooked)1 cup0μg (0% DV)
Shiitake Mushrooms (Cooked)1 cup0μg (0% DV)
Tomatoes (Raw)1 cup14μg (12% DV)
Tomatoes (Cooked)1 cup7μg (6% DV)
Cucumbers (Raw)1 cup17μg (14% DV)
Iceberg Lettuce (Raw)1 cup shredded17.4μg (14% DV)
Artichokes1 medium18.9μg (16% DV)
See the full list of vegetables low in vitamin K or check the nutrition facts for individual foods. Low vitamin K does not necessarily guarantee safe administration of Warfarin (Coumadin).

Fruits Low in Vitamin K

FoodServing SizeVitamin K Content
Watermelon1 cup diced0.2μg (0% DV)
Litchis1 cup0.8μg (1% DV)
Bananas1 medium (105g)0.6μg (1% DV)
Pineapple1 cup1.2μg (1% DV)
Apples1 medium (182g)4μg (3% DV)
Nectarines1 medium (142g)3μg (3% DV)
Strawberries 1 cup3μg (3% DV)
Peaches1 medium (150g)4μg (3% DV)
Avoid grapefruit and cranberries.
Citrus fruits, like oranges, should also be limited or avoided. Approach mangoes, blueberries, and pomegranate with caution as these fruits can also affect PT/INR.
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:
FoodServing SizeVitamin K Content
White Rice1 cup0μg (0% DV)
Brown Rice1 cup0.4μg (1% DV)
Couscous1 cup0.2μg (0% DV)
Cornmeal (White or Yellow)1 cup0.4μg (0% DV)
Bulgur1 cup0.9μg (1% DV)
Pearled Barley1 cup1.3μg (1% DV)
Pasta (Plain)1 cup0μg (0% DV)
Whole Wheat Bread1 Slice0μg (0% DV)
Buckwheat1 cup3.2μg (4% DV)
Millet1 cup0.5μg (1% DV)
Quinoa1 cup0.0μg (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.

Warnings

  • 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.
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Data Sources and References

  1. U.S. Agricultural Research Service Food Data Central
  2. ODS Fact Sheet on Coumadin (Legacy file hosted on MyFoodData.com)

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