Interactions of Warfarin and Herbs, Dietary Supplements, Foods & Vitamins

There is limited evidence on the exact effect herbs, dietary supplements, foods, and vitamins have on warfarin. They may potentially affecting the effectiveness of warfarin by altering the clearance/metabolism of warfarin through various pathways, reducing the absorption of warfarin, containing warfarin constituents themselves, inhibiting the synthesis of vitamin K-dependent coagulation factors, increasing the dietary intake of vitamin K and reducing the effectiveness of warfarin, or inhibiting/decreasing the platelet function.

The safest is to avoid all herbal and dietary supplements, of course except foods, unless their physicians approve. However, if herbal and dietary supplements are taken regularly on a daily basis, they pose less of a problem than if taken off and on.

The following interaction chart is intended as a quick reference to highlight potential interactions between warfarin and commonly known herbal, dietary supplements, foods, and vitamins. Most of the potential interactions stated in the following chart have no published human case reports of an interaction with warfarin, and caution with using these supplements in combination with warfarin is warranted.

**Most of the uses of various supplements stated in the following interaction chart are insufficient of evidence. More evidence is needed to rate the effectiveness of the supplements for their respective uses.

Warfarin Interaction Chart with Herbs, Dietary Supplements & Foods 1, 2, 3, 4

Herb/Supplement/ Food/ Vitamin

Herbal/Supplemental/Vitamin Uses Potential Interactio

n

Mechanism

Agar To curb appetite & promote weight loss. ↓ INR May ↓ absorption of warfarinAgrimony To treat winter colds, fevers, diarrhea, sores, blemishes & pimples.

To stop bleeding in Chinese herbal medicine.↓ INR May be a coagulant

Alcohol (acute) - ↑ INR May ↓ warfarin metabolism when consumed excessivelyAlcohol (chronic) - ↓ INR May ↑ warfarin metabolism by inducing CYP enzymeAlfalfa (Medicago sativa) To treat disorders related to the digestive tract and the kidneys. ↑↓ INR ↑ INR → May contain warfarin constituents

↓ INR → May be due to the Vitamin K content in herbAlgin To lower cholesterol & blood pressure.

To reduce the amount of heavy chemicals taken up by the body.↓ INR May ↓ absorption of warfarin

Aloe To treat osteoarthritis, bowel diseases, fever, itching, inflammation, stomach ulcers, diabetes & asthma.

↓ INR May ↓ absorption of warfarin

Anise (Aniseed) As a digestive aid and anti-flatulence agent.To relieve coughs & colds. To prevent insomnia.

↑ INR May contain warfarin constituents

Arnica (Wolf bane) Used in homeopathic preparations to treat sore muscles & bruises. ↑ INR May contain warfarin constituentsArtemesia To treat malaria & bacterial/fungal/viral infections. ↑ INR May contain warfarin constituentsAsafoetida To treat bronchitis, H1N1 swine flu, asthma & digestive disorders. ↑ INR May contain warfarin constituentsAvocado - ↓ INR May ↑ warfarin metabolismBarley To lower blood sugar, blood pressure & cholesterol.

To promote weight loss & treat diarrhea and stomach pain.↓ INR May ↓ absorption of warfarin

Bishop’s weed (Bergapten) To treat digestive disorders, asthma, angina, kidney stones & as a diuretic.

↑ INR May contain warfarin constituentsMay ↓ warfarin metabolism (P450 3A4 inhibitor)

Bitter Orange To improve appetite, and in contrast, also used for weight loss.To treat upset stomach & nasal congestion

↑ INR May ↓ warfarin metabolism (P450 3A4 inhibitor)

Black cohosh (cimicifuga racemosa)

To treat symptoms of menopause, premenstrual syndrome, painful menstruation, acne, osteoporosis & induce labor.

↑ INR May contain salicylates constituents

Bladderwrack (Fucus, Kelp)

To treat thyroid disorders, obesity, arthritis, joint pain, arteriosclerosis, digestive disorders, heartburn, constipation, bronchitis, emphysema, UTI & anxiety.

↑ INR May have anticoagulant effects

Blond psyllium As a laxative & for softening stools. ↓ INR May ↓ absorption of warfarin

Supplement Uses Potential Interactio

n

Mechanism

Bogbean To treat rheumatoid arthritis, loss of appetite & upset stomach. ↑ INR May contain warfarin constituentsBromelain To reduce swelling/inflammation of nose & sinuses. ↑ INR May ↓ platelet aggregationBuchu To treat cystitis, urethritis, prostatitis & pyelonephritis. ↑ INR May contain warfarin constituentsBurdock To increase urine flow, kill germs, reduce fever & “purify” blood. ↑ INR May ↓ platelet aggregationButternut To treat constipation, gallbladder disorders & hemorrhoids. ↓ INR May ↓ absorption of warfarinCaffeine To improve mental alertness. ↑ INR May have antiplatelet effectsCapsicum To treat digestive disorders. ↑ INR May contain warfarin constituentsCascara As a laxative for constipation. ↓ INR May ↓ absorption of warfarinCassia To treat digestive disorders, common cold & loss of appetite. ↑ INR May contain warfarin constituents

May inhibit platelet aggregrationCastor Used for birth control, constipation, leprosy & syphilis. ↓ INR May ↓ absorption of warfarinCat’s Claw To treat osteoarthritis, rheumatoid arthritis & digestive disorders. ↑ INR May ↓ warfarin metabolism (P450 3A4 inhibitor)Celery (seed/extract) To treat joint pain, gout, headache, nervousness & exhaustion. ↑ INR May contain warfarin constituentsChamomile (Matricaria recutita)

To treat digestive disorders, travel sickness, stuffy nose, hay fever, ADHD, restlessness & trouble sleeping.

↑ INR May contain warfarin constituents

Chondroitin To treat osteoarthritis. ↑ INR May increase bleeding & chondroitin sulfate is a component of the antithrombotic danaparoid

Chrysin To treat anxiety, gout, baldness & erectile dysfunction. ↑ INR May ↓ warfarin metabolism (P450 3A4 inhibitor)Clove To treat upset stomach, diarrhea, hernia & bad breath. ↑ INR Contains eugenol – a platelet inhibitor Cod Liver Oil (Fish oil) To treat high cholesterol, high triglycerides, high blood pressure,

heart disease, kidney disease, osteoarthritis & depression.↑ INR May inhibit platelet aggregration

Co-enzyme Q10 (Ubiquinone)

To treat blood vessel conditions such as CHF, angina & high blood pressure.

↓ INR May have Vitamin K-like procoagulant effects.

Coffee Charcoal To treat diarrhea. ↓ INR May ↓ absorption of warfarinColtsfoot To treat bronchitis, asthma, whooping cough. ↑ INR May inhibit platelet aggregrationCranberry To prevent and treat UTI. ↑ INR May ↓ warfarin metabolism (P450 2C9 inhibitor)Dandelion To treat loss of appetite, upset stomach, gallstones, joint pain,

muscle aches, eczema & bruises.↑↓ INR ↑ INR → May contain warfarin constituents

↓ INR → May be due to the Vitamin K content in herb

Supplement Uses Potential Interactio

n

Mechanism

Danshen (Salvia miltiorrhiza)

To treat stroke, angina, menstrual disorders & liver disease. ↑ INR May contain warfarin constituentsMay inhibit platelet aggregration

Dehydroepiandrosterone (DHEA)

To slow or reverse aging, to improve thinking skills in older people, to slow the progress of Alzheimer’s disease.

↑ INR May ↓ warfarin metabolism (P450 3A4 inhibitor)

Devil’s Claw As an analgesic in treating gout, arthritis & myalgias. ↑ INR May ↓ warfarin metabolism (P450 2C9 inhibitor)Dong Quai (Angelica sinesis)

To lower symptoms of menopause, relieves menstrual cramp, and regulates menstrual periods.Combined with other herbs to treat conditions such as high blood pressure, arthritis, allergies and asthma.

↑ INR May contain warfarin constituentsMay inhibit platelet aggregration

Echinacea (Purple coneflower)

To treat infections, especially common cold & other upper respiratory infections.

↑ INR May ↓ warfarin metabolism (P450 3A4 inhibitor)

Eucalyptus To treat infections, fever, upset stomach & cough. ↑ INR May ↓ warfarin metabolism (P450 1A2, 2C9, 3A4 inhibitor)European Buckthorn To treat constipation. ↓ INR May ↓ absorption of warfarinEvening Primrose Oil To treat breast pain, osteoporosis, eczema, psoriasis & acne. ↑ INR May ↓ platelet aggregationFenugreek To treat diabetes, loss of appetite, heartburn, constipation,

atherosclerosis, hyperlidemia & promote lactation.↑ INR May contain warfarin constituents

May have antiplatelet effectsFeverfew (Tanacetum parthenium)

To prevent migraine headaches. To treat fever, irregular menstrual periods, arthritis, psoriasis & asthma.

↑ INR May inhibit platelet release and aggregrationMay ↓ warfarin metabolism (P450 1A2, 2C9, 3A4 inhibitor)

Flaxseed To treat GI tract disorders. ↑ INR May ↓ platelet aggregation & ↑ bleeding timeFo-Ti To treat tuberculosis, prostatis & constipation. ↑ INR May ↓ warfarin metabolism (P450 1A2, 2C9, 3A4 inhibitor)Garlic (Allium sativum) To treat hypertension & hyperlipidemia.

To prevent coronary heart disease, age-related vascular changes & atherosclerosis.

↑ INR May have anticoagulant effects & inhibit platelet aggregration May ↓ warfarin metabolism (P450 2C9, 3A4 inhibitor)

Ginger (Zingiber officinale) To treat motion/morning sickness, upset stomach, diarrhea, nausea, cough & bronchitis.

↑ INR May inhibit thromboxane synthetase & ↓ platelet aggregration

Gingko biloba (Maidenhair Tree)

To enhance memory & improve cognition. ↑ INR Ginkolide B may inhibit platelet activating factor by displacement from its receptor binding sites

Ginseng, American (Panax quinquefolinus)

Used for stress, to boost immune system, to prevent and treat cold & flu, to improve digestion and for loss of appetite.

↑↓ INR↑ INR → may decrease platelet aggregration↓ INR → may antagonize the anticoagulant effects of warfarinGinseng, Oriental

(Panax ginseng)To improve thinking, concentration, memory, work efficiency, physical stamina & athletic endurance.

Supplement Uses Potential Interactio

n

Mechanism

Ginseng, Eleuthero or Siberian (Eleutherococcus senticosus)

To strengthen the body & increase general resistance to daily stress.To treat high blood pressure, low blood pressure, atherosclerosis & rheumatic heart disease.

↑ INR May inhibit platelet aggregration & contain warfarin constituents

Glucosamine To treat osteoarthritis, knee pain, back pain & glaucoma. ↑ INR May contain heparin constituentsGoldenseal To treat upper respiratory tract infections & digestive disorders. ↑ INR May ↓ warfarin metabolism (P450 3A4 inhibitor)Grapefruit juice To treat high cholesterol, atherosclerosis, psoriasis, cancer, weight

loss & obesity.↑ INR May ↓ warfarin metabolism (P450 1A2, 2A6, 3A4 inhibitor)

Green Tea To improve mental alertness and thinking.To treat weight loss, stomach disorders, headaches & osteoporosis

↓ INR May contain substantial amounts of vitamin K

Guggul To treat arthritis, high cholesterol atherosclerosis & acne. ↓ INR May ↑ warfarin metabolism (P450 3A4 inducer)Horse chestnut To treat varicose veins, hemorrhoids & phlebitis. ↑ INR May contain warfarin constituentsHorseradish To treat UTI, kidney stones, cough, bronchitis & gout. ↑ INR May contain warfarin constituentsIceland Moss To treat irritation of mouth & throat, dry cough & common cold ↓ INR May ↓ absorption of warfarinIpriflavone To prevent and treat osteoporosis. ↑ INR May ↓ warfarin metabolism (P450 1A2, 2C9 inhibitor)Karaya Gum As a bulk-forming laxative to relieve constipation. ↓ INR May ↓ absorption of warfarinKava To treat anxiety, stress, restlessness & insomnia. ↑ INR May ↓ warfarin metabolism (P450 1A2, 2C9, 3A4 inhibitor)Larch Arabinogalactan To treat common cold, flu, H1N1 (swine) flu & ear infections. ↓ INR May ↓ absorption of warfarinLicorice ( Glcyrrhiza glabra)

To treat stomach ulcers, heartburn, chronic gastritis, sore throat, bronchitis, osteoarthritis, SLE, liver disorders & tuberculosis.

↑ INR May contain warfarin constituentsMay inhibit platelet aggregrationMay ↓ warfarin metabolism (P450 3A4 inhibitor)

Lime To treat severe diarrhea. ↑ INR May ↓ warfarin metabolism (P450 3A4 inhibitor)Limonene To treat weight loss, cancer & bronchitis. ↓ INR May ↑ warfarin metabolism (P450 2C9 inducer)Lovage root To treat urinary tract inflammation & kidney stones. ↑ INR May contain warfarin constituentsLycium (Chinese Wolfberry)

To treat diabetes, high blood pressure, fever & malaria. ↑ INR May ↓ warfarin metabolism (P450 2C9 inhibitor)

Mango - ↑ INR May ↓ warfarin metabolism (P450 2C9 inhibitor)Marshmallow To treat inflammation of respiratory tract, stomach & urinary tract. ↓ INR May ↓ absorption of warfarinMeadowsweet To treat colds, bronchitis, upset stomach, heartburn & gout. ↑ INR May contain warfarin constituentsMelatonin To treat insomnia or sleep problems in children with developmental

disorders & blind people.↑ INR May ↑ the anticoagulant or antiplatelet effect

May ↓ prothrombin activityMelilot ( Sweet clover) As a diuretic & to relieve symptoms of poor blood circulation. ↑ INR May contain warfarin constituents

Supplement Uses Potential Interactio

Mechanism

nMilk Thistle To treat liver disorders, heartburn & diabetes. ↑ INR May ↓ warfarin metabolism (P450 2C9, 3A4 inhibitor)Nattokinase To treat cardiovascular diseases. ↑ INR may have thrombolytic activityNettle To treat urination problems related to BPH. ↑↓ INR ↑ INR → May contain warfarin constituents

↓ INR → May be due to the Vitamin K content in herbNoni Juice To treat arthritis, diabetes, high blood pressure & heart diseases. ↓ INR May ↓ effectiveness of warfarin. Mechanism unknownOnion To treat digestive disorders & heart and blood vessel problems. ↑ INR May ↓ platelet aggregationPantethine To lower cholesterol, prevent inflammation, boost immune system,

treat GI diseases & improve energy.↑ INR May ↓ platelet aggregation

Papain/Papaya To treat herpes zoster, pharyngitis, digestive problems, hay fever & runny nose.

↑ INR Effect of ↑ INR has only been reported in a single case with papaya extract, not with the fruit. May cause gastrointestinal mucous membrane damage and bleeding.

Parsley To treat UTI, kidney stones, GI disorders & menstrual problems. ↑ INR May contain warfarin constituentsPassionflower To treat insomnia, anxiety & relieve symptoms related to narcotic

drug withdrawal.↑ INR May contain warfarin constituents

Peppermint To treat heartburn, IBS, common cold, cough, nausea & vomiting. ↑ INR May ↓ warfarin metabolism (P450 1A2, 2C9, 3A4 inhibitor)Policosanol To treat high cholesterol & narrowing of blood vessels. ↑ INR May inhibit platelet aggregationPoplar To treat cough & chest congestion. ↑ INR May contain salicylates constituents & ↓ platelet aggregationQuassia To treat anorexia, indigestion, constipation & fever. ↑ INR May contain warfarin constituentsRed clover (Promensil) To treat high cholesterol, indigestion, cough, asthma & bronchitis. ↑ INR May contain warfarin constituents

May ↓ warfarin metabolism (P450 1A2, 2C9, 3A4 inhibitor)Resveratrol To treat atherosclerosis & high cholesterol. ↑ INR May have antiplatelet effects

May ↓ warfarin metabolism (P450 1A2, 3A4 inhibitor)Rue To treat digestive problems & heart and circulation problems. ↑ INR May contain warfarin constituentsSaw palmetto To decrease symptoms of BPH & treat prostate infections. ↑ INR May have anticoagulant effectsSea buckthorn To treat arthritis, GI ulcers & gout. ↑ INR May inhibit platelet aggregationSlippery Elm To treat sore throat, cough, IBS & UTI. ↓ INR May ↓ absorption of warfarinSoy (Milk/Tofu) - ↓ INR May contain substantial amounts of vitamin KSpirulina To treat precancerous mouth lesions, boost immune system,

improve memory, increase energy & improve digestion.↓ INR May ↓ effectiveness of warfarin due to the Vitamin K content

St. John’s Wort To treat depression, anxiety, moodiness & menopausal symptoms. ↓ INR May ↑ warfarin metabolism (P450 1A2, 2C9, 3A4 inducer)Sulforaphane To prevent prostate cancer & other types of cancer. ↑ INR May ↓ warfarin metabolism (P450 1A2 inhibitor)

Supplement Uses Potential Interactio

Mechanism

nTonka Bean To treat cramps, nausea, cough, spasms & tuberculosis. ↑ INR May contain warfarin constituentsTragacanth To treat diarrhea & constipation. ↓ INR May ↓ absorption of warfarinTurmeric To treat heartburn, digestive problems & liver problems. ↑ INR May ↓ platelet aggregationValerian To treat insomnia, anxiety & psychological stress. ↑ INR May ↓ warfarin metabolism (P450 3A4 inhibitor)Vinpocetine To enhance memory & prevent Alzheimer’s disease. ↑ INR May have antiplatelet effectsVitamin A To treat vitamin A deficiency, improve visions, treat eye disorders

& reduce complications of malaria, HIV & measles in children.↑ INR May ↓ warfarin metabolism (P450 2C9 inhibitor)

Vitamin C To treat and prevent vitamin C deficiency, improve absorption of iron, treat and prevent common cold.

↓ INR May ↓ effectiveness of warfarin. However, in recent studies, no effect was found with doses up to 1000mg per day.

Vitamin E To treat Vitamin E deficiency, bladder cancer, Alzheimer’s disease, dysmenorrheal, premenstrual syndrome, ischemic stroke, male infertility, dementia & Parkinson’s disease.

↑ INR May ↓ platelet aggregration & antagonize the effects of vitamin-K dependent clotting factors. Dose-dependent and significant with doses > 800 units/day.

Wild Carrot To treat kidney stones, bladder problems & gout. ↑ INR May contain warfarin constituentsWild Cherry To treat colds, whooping cough & bronchitis ↑ INR May ↓ warfarin metabolism (P450 3A4 inhibitor)Wild Lettuce To treat whooping cough, asthma, insomnia & restlessness. ↑ INR May contain warfarin constituentsWillow/Wintergreen To treat headache, nerve pain, arthritis & menstrual cramp. ↑ INR May contain salicylates constituentsWoodruff To treat disorders of lung, stomach, liver, gallbladder & urinary. ↑ INR May contain warfarin constituentsYarrow To treat fever, common cold, hay fever, dysentery & diarrhea. ↓ INR May be a coagulant

References

1. Nutescu EA, Shapiro NL, Ibrahim S, West P. Warfarin and its interactions with foods, herbs and other dietary supplements. Expert Opin. Drug

Saf. (2006) 5(3): 433-451.

2. Jensen B. Herbal Drug Interaction Chart. July 2003.

3. Find a Vitamin Supplements. WebMD, LLC, 2005 – 2011. http://www.webmd.com/vitamins-supplements. Accessed 10 November 2011.

4. Alternative Nature Online Herbal. Karen Bergeron, Alternative Nature Enterprise, 1997 – 2011. http://www.altnature.com/gallery/index.html.

Accessed 10 November 2011.

Interactions of warfarin and dietary vitamin K

Warfarin is affected by vitamin K. A high vitamin K intake in patient’s diet can affect the body response to warfarin and lower the INR result.

When a patient begins warfarin therapy, baseline education should include information on vitamin K-rich sources. A chart or leaflet identifying foods high in vitamin K can be a helpful reference for the patient. The primary sources of vitamin K-containing foods are dark green vegetables and oils.1

To avoid the risks of INR fluctuation at subsequent visits, it is necessary to advise patients to take a consistent and stable vitamin K diet. Counseling patients on avoidance of vitamin K foods is not recommended as this may prevent intake of other essential vitamins and minerals in the foods.1

It would be the best to advise patients to keep a consistent amount of vitamin K consumption throughout the week by selecting 2 or 3 days that allow the patient to eat 1 – 2 servings of vitamin-containing foods.1 However, for those patients that are vegetarians or insist on eating vegetables everyday, they can be suggested to take vitamin K-containing foods consistently everyday without exceeding the recommended servings and they must be emphasized on avoiding sudden and drastic changes in vegetables intake.

Below is the recommended servings based on vitamin K content: 2, 3

Level Vitamin K content Recommended No. of serving(s) per day

High > 100 mcg No more than 1 serving

Medium 25 – 100 mcg No more than 3 servings

Low 0 – 24 mcg No limit

The vitamin K content of common foods (vegetables, fats and oils, beverages, meats, fruits, nuts, grain products and legumes, and dairy products) is shown in the following tables.

Vegetables

Vegetables are one of the important food groups to watch for vitamin K content. Green leafy vegetables are high in vitamin K. Many other vegetables have a medium amount of vitamin K.4, 5

Vegetable Vegetable PreparationServing

size

Estimated weight

(g)

Vitamin K (mcg)

Level

AsparagusFrozen→cooked→boiled→drained→without salt

1 cup 180 144 High4 spears 60 48 Medium

Cooked→boiled→drained 4 spears 60 30.4 MediumCanned→drained solids 4 spears 72 29.7 Medium

Beans

Snap→green→canned→regular packed→drained solids 1 cup 135 52.5 MediumSnap→green→cooked→boiled→drained→without salt 1 cup 125 20 LowSnap→yellow→cooked→boiled→drained→without salt 1 cup 125 20 LowSnap→yellow→canned→regular packed→drained solids 1 cup 135 13.4 LowKidney→red→mature seeds→cooked→boiled→without salt 1 cup 177 14.9 LowKidney→red→mature seeds→canned 1 cup 256 11 Low

Beet Greens Cooked→boiled→drained→without salt 1 cup 144 697 High

BroccoliCooked→boiled→drained→without salt 1 cup 156 220.1 HighFrozen→chopped→cooked→boiled→drained→without salt 1 cup 184 162.1 HighRaw 1 cup 188 89.4 Medium

Brussel Sprouts

Frozen→cooked→boiled→drained→without salt 1 cup 155 299.9 HighCooked→boiled→drained→without salt 1 cup 156 218.9 High

Cabbage

Cooked→boiled→drained→without salt 1 cup 150 163.1 HighChinese (pak-choi)→cooked→boiled→drained→without salt 1 cup 170 57.8 MediumRaw 1 cup 70 53.2 MediumSavoy→raw 1 cup 70 48.2 MediumRed→raw 1 cup 70 26.7 Medium

Carrots

Juice→canned 1 cup 236 36.6 MediumCooked→boiled→drained→without salt 1 cup 156 21.4 LowFrozen→cooked→boiled→drained→without salt 1 cup 146 19.9 Low

Raw1 cup 110 14.5 Low

1 carrot 72 9.5 LowCanned→regular packed→drained solids 1 cup 146 14.3 Low

CauliflowerFrozen→cooked→boiled→drained→without salt 1 cup 180 21.4 LowCooked→boiled→drained→without salt 1 cup 124 17.1 LowRaw 1 cup 100 15.5 Low

CeleryCooked→boiled→drained→without salt

1 cup 150 56.7 Medium1 stalk 37.5 14.2 Low

Raw1 cup 120 35.2 Medium1 stalk 40 11.7 Low

Coleslaw Fast foods ¾ cup 99 70.2 Medium

Collards Frozen→chopped→cooked→boiled→drained→without salt 1 cup 170 1059.4 HighCooked→boiled→drained→without salt 1 cup 190 836 High

CucumberWith peel→raw

1 large 301 49.4 Medium1 cup 104 17.1 Low

Peeled→raw1 large 280 20.2 Low1 cup 119 8.6 Low

Eggplant Cooked→boiled→drained→without salt 1 cup 99 2.9 LowEndive Raw 1 cup 50 115.5 HighGarlic Raw 1 clove 3 0.1 Low

Vegetable Vegetable PreparationServing

size

Estimated weight

(g)

Vitamin K (mcg)

Level

KaleFrozen→cooked→boiled→drained→without salt 1 cup 130 1146.6 HighCooked→boiled→drained→without salt 1 cup 130 1062.1 High

Lettuce

Butterhead→raw 1 head 163 166.7 High

Iceberg→raw1 head 539 129.9 High1 cup 55 13.3 Low

Green leaf→raw 1 cup 56 97.2 MediumCos or romaine→raw 1 cup 56 57.4 Medium

Mung Beans

Sprouted→raw 1 cup 104 34.3 MediumSprouted→cooked→boiled→drained→ without salt 1 cup 124 28.1 Medium

Mushrooms

White→raw 1 cup 70 0 LowWhite→cooked→boiled→drained→without salt 1 cup 156 0 LowCanned →drained solids 1 cup 156 0 LowShiitake→cooked→without salt 1 cup 145 0 LowSoup/cream→canned→with equal volume of low fat milk 1 cup 248 2.2 LowSoup/cream→canned→with equal volume water 1 cup 244 2.0 Low

Mustards Green→cooked→boiled→drained→without salt 1 cup 140 419.3 High

OnionsSpring or scallions→raw

1 cup 100 207 High1 whole 15 31.1 Medium

Cooked→boiled→drained→without salt 1 cup 210 1.1 LowRaw 1 cup 160 0.6 Low

Parsley Raw 10 sprigs 10 164 High

PeasGreen→canned →drained solids→unprepared 1 cup 170 62.6 MediumGreen→frozen→cooked→boiled→drained→without salt 1 cup 160 38.4 Medium

Peppers

Sweet→green→cooked→boiled→drained→without salt 1 cup 136 13.3 LowSweet→green→raw 1 cup 149 11.0 LowSweet→red→raw 1 cup 149 7.3 LowSweet→red→cooked→boiled→drained→without salt 1 cup 136 6.9 LowHot chili→green→raw 1 pepper 45 6.4 LowHot chili→red→raw 1 pepper 45 6.3 Low

Potatoes

Fast foods→french fried in vegetable oil1 large 169 18.9 Low

1 medium 134 15 LowFast foods→hashed brown ½ cup 72 7.1 LowMashed→home prepared→whole milk & margarine added 1 cup 210 12.6 LowHashed brown→home prepared 1 cup 156 5.8 LowSweet→canned→vacuum pack 1 cup 255 5.6 LowSweet→canned→syrup pack→drained solids 1 cup 196 5.1 LowSweet→cooked→baked in skin→without salt 1 potato 146 3.4 LowSweet→cooked→bolied→without skin 1 potato 156 3.3 LowBaked→flesh and skin→without salt 1 potato 202 4 LowBoiled→cooked without skin→flesh→without salt 1 potato 135 2.8 LowBoiled→cooked in skin→flesh→without salt 1 potato 136 2.9 Low

PumpkinCanned→without salt 1 cup 245 39.2 MediumCooked→boiled→drained→without salt 1 cup 245 2.0 Low

Sauerkraut Canned→solids and liquids 1 cup 236 30.7 MediumSeaweed Dried 1 cup - 28 MediumSoybean Mature cooked→boiled→without salt 1 cup 172 33 Medium

Vegetable Vegetable PreparationServing

size

Estimated weight

(g)

Vitamin K (mcg)

Level

Spinach

Frozen→chopped→cooked→boiled→drained→without salt 1 cup 190 1027.3 HighCanned→regular pack→ drained solids 1 cup 214 987.8 HighCooked→boiled→drained→without salt 1 cup 180 888.5 HighRaw 1 cup 30 144.9 High

Swiss Chard

Raw 1 cup - 299 High

Tomatoes

Canned→paste→without salt added 1 cup 262 29.9 MediumCanned→puree→without salt added 1 cup 250 8.5 LowCanned→sauce 1 cup 245 6.9 Low

Red→ripe→raw→year round average1 cup 180 14.2 Low

1 tomato 123 9.7 LowRed→ripe→canned→packed in tomato juice 1 cup 240 7 LowRed→ripe→canned→stewed 1 cup 255 6.1 LowJuice→canned→with salt added 1 cup 243 5.6 LowSoup→canned→with equal volume of low fat milk 1 cup 248 4 LowSoup→canned→with equal volume of water 1 cup 244 3.7 Low

TurnipGreen→frozen→cooked→boiled→drained→without salt 1 cup 164 851 HighGreen→ cooked→boiled→drained→without salt 1 cup 144 529.3 HighCooked→boiled→drained→without salt 1 cup 156 0.2 Low

Fats and Oils

Fats and oils eaten in small amounts are low in vitamin K. However, large amounts can have a medium to high amount of vitamin K. Sometimes, patients may eat more vitamin K than they realize, like when they eat salads that use a lot of oil or mayonnaise such as potato salad or coleslaw.4

Fats and Oils Serving size Vitamin K (mcg) Level

Butter1 cup 16 Low

1 tablespoon 1 low

Canola Oil1 cup 55 Medium

1 tablespoon 4 Low

Corn Oil1 cup 4 Low

1 tablespoon Less than 1 Low

Margarine1 cup 211 High

1 tablespoon 13 Low

Mayonnaise1 cup 93 Medium

1 tablespoon 6 low

Olive Oil1 cup 130 High

1 tablespoon 8 Low

Peanut Butter1 cup 2 Low

1 tablespoon Less than 1 Low

Peanut Oil1 cup 2 Low

1 tablespoon Less than 1 Low

Safflower Oil1 cup 16 Low

1 tablespoon 1 Low

Sesame Oil1 cup 30 Medium

1 tablespoon 2 Low

Soybean Oil1 cup 431 High

1 tablespoon 27 Medium

Beverages

Most beverages are low in vitamin K.4

* 1 fluid oz. = approx. 29.5 ml

Meats

Meat is low in vitamin K.4

Nuts

Nuts have a low to medium amount of vitamin K.4

Beverage Serving size Vitamin K (mcg) LevelBeer 12 fluid oz. Less than 1 LowCoffee 6 fluid oz. Less than 1 LowCola 12 fluid oz. Less than 1 LowMilk 1 cup Less than 1 LowOrange Juice 1 cup Less than 1 LowTea 6 fluid oz. Less than 1 LowWater 8 fluid oz. Less than 1 LowWine 3.5 fluid oz. Less than 1 Low

Meat Serving size Vitamin K (mcg) LevelBacon 1 cup (diced) Less than 1 LowBeef 1 cup (diced) 2 LowBeef Liver 1 cup (diced) 5 LowChicken 1 cup (diced) 3 LowChicken Liver 1 cup (diced) 3 LowDuck 1 cup (diced) 6 LowFish 1 cup (diced) Less than 1 LowLamb 1 cup (diced) 6 LowPork 1 cup (diced) Less than 1 LowShrimp 1 cup (diced) Less than 1 LowTurkey (dark meat)

1 cup (diced) 5 Low

Turkey (light meat)

1 cup (diced) Less than 1 Low

Venison 1 cup (diced) 2 Low

Nut Serving size Vitamin K (mcg) LevelAlmonds 1 cup Less than 1 LowCashews 1 cup 45 MediumHazelnuts 1 cup 16 LowMacadamia 1 cup Less than 1 LowPeanuts 1 cup Less than 1 LowPecans 1 cup 3 LowPistachios 1 cup 17 LowWalnuts 1 cup 3 Low

Fruits

Most fruits are low in vitamin K.4

**Mango has been associated with an increased INR in 13 patients, with a rechallenge in 2 patients showing similar results. Patients were consuming 1 – 6 mangos per day for 2 days to 1 month before the INR was tested. INR values decreased in all 13 patients after discontinuing mango ingestion. The mechanism for this interaction has been theorized to be related to the high amount of vitamin A in mangos, which inhibits P450 2C9 enzyme and decreasing warfarin metabolism. It is prudent to advise patients to limit their intake of mangos, or alternatively, keep a consistent weekly intake, to minimize INR fluctuation.2

Grain Products and Legumes

Bread, grain products such as oatmeal and rice, and legumes such as beans and lentils, are low in vitamin K.4

Fruit Serving size Vitamin K (mcg) LevelApple 1 cup 3 LowBanana 1 cup Less than 1 LowBlueberries 1 cup 28 MediumCantaloupe 1 cup 4 LowGrapefruit 1 cup Less than 1 LowGrapes 1 cup 23 MediumLemon 1 cup Less than 1 LowLime 1 cup Less than 1 LowMango** 1 cup 7 LowOrange 1 cup Less than 1 LowPeach 1 cup 4 LowPear 1 cup 7 LowRaspberries 1 cup 10 LowStrawberries 1 cup 3 LowWatermelon 1 cup Less than 1 Low

Grain Product and Legume

Serving size Vitamin K

(mcg)Level

Bagel (plain) 1 each 1 LowBeans (black) 1 cup 3 LowBeans (white) 1 cup 6 LowBread (assorted) 1 slice Less than 1 LowFlour (white) 1 cup Less than 1 LowFlour (whole wheat) 1 cup 2 LowLentils (cooked) 1 cup 3 LowOatmeal 1 cup 1 LowPasta 1 cup Less than 1 LowRice (brown) 1 cup 1 LowRice (white) 1 cup Less than 1 LowRice (wild) 1 cup Less than 1 Low

Dairy Products

Dairy products are low in vitamin K.4

References

1. Nutescu EA, Shapiro NL, Ibrahim S, West P. Warfarin and its interactions with foods, herbs and other dietary supplements. Expert Opin. Drug Saf. (2006) 5(3): 433-451.

2. Warren Grant Magnuson Clinical Center, National Institute of Health. Important Information to know when you are taking: Coumadin and Vitamin K. December 2003.

3. Stony Brook University Medical Center. Food Interactions with Warfarin. 7 January 2009.

4. University Health Care Thrombosis Service. Vitamin K Content of Common Foods. http://healthcare.utah.edu/Thrombosis/patients/warfarin/WarfarinGuide_vitaminK.pdf. Accessed 11 November 2011.

5. USDA National Nutrient Database for Standard Reference, Release 23. U.S. Department of Agriculture. http://www.ars.usda.gov/SP2UserFiles/Place/12354500/Data/SR23/nutrlist/sr23a430.pdf. Accessed 11 November 2011.

HELP ME TO REMOVE / ADD IN ANYTHING U TINK IS NECESSARY

Dairy Product Serving size Vitamin K (mcg) LevelCheese 1 cup 3 LowCream 1 cup 8 LowEgg (cooked) 1 (large) 1 LowEggs (cooked) 1 cup 4 LowIce Cream (chocolate) 1 cup Less than 1 LowIce Cream (vanilla) 1 cup Less than 1 LowMilk (2%) 1 cup Less than 1 LowMilk (non-fat) 1 cup Less than 1 LowMilk (whole) 1 cup Less than 1 LowYogurt 1 cup Less than 1 Low