Warfarin and Vitamin K – Why You Need Both

If you’ve been diagnosed with a blood clot, chances are you are taking a blood thinner, which is very commonly Coumadin or warfarin. If you’re like me and have been diagnosed with a clotting disorder or have a high chance of reoccurring blood clots, you might even be taking warfarin for the rest of your life. The prospect of having to monitor a potentially dangerous condition, let alone take medication forever, is overwhelming and worrisome for many, including myself. Warfarin can be difficult to manage, is not entirely safe for your liver over an extended period, and has some pretty notable interactions with other vital nutrients, mainly vitamin K. In fact, you may have even been told by a medical professional to stop eating foods high in vitamin K. While warfarin and vitamin K do interact, the potential harm of completing eliminating vitamin K from your diet may be proven to be more dangerous than creating a consistent level of it in your blood.

Why Vitamin K Matters

Vitamin K is a naturally occurring vitamin most commonly found in green, leafy vegetables such as spinach, broccoli, and lettuce (see an extensive list of foods here). Your body uses vitamin K from foods you eat and also bacteria in your intestines to produce some of the factors that help your blood clot.

Why Warfarin Matters

Warfarin interferes with how your body uses vitamin K by preventing the production of vitamin K clotting factors in your liver. This can cause clotting to occur at a much slower rate and creates the potential for unwanted bleeding problems or additional clotting in your veins.

How Does Vitamin K Affect My INR?

Changes in the amount of vitamin K you consume through your diet can alter the liver’s ability to process warfarin and change the amount of blood-thinning properties in your body. Your INR refers to a standardized way to measure how quickly your blood is clotting. The lower your INR, the more quickly the blood clots or the “thicker” the blood. If your INR is too low, you could be at risk for further clotting. The higher your INR, the longer it takes the blood to clot or the “thinner” the blood, putting you at risk for bleeding problems. With an increase in vitamin K, your INR level may drop, creating the potential for unwanted clotting.  A decrease in vitamin K intake may increase your INR, creating the potential for unwanted bleeding.

What We’ve Been Told

Most of us have been told to avoid vitamin K like the plague.

Beyond the Blood Thinner – Why You Need Vitamin K

We are taking warfarin, it’s depleting our body’s natural vitamin k stores – which are important for a variety of things, most notably preventing the hardening of arteries in the heart, potentially creating serious health implications – and we are being told not to replace it.

A New Way of Thinking

It is not about eliminating vitamin K from your diet. It is about consistency. For example, if you eat two servings of foods per day that are high in vitamin K, you should continue doing that. If you don’t eat foods rich in vitamin K at all, do not suddenly decide to eat large amounts of them. Clot Care also confirms, “It is a common misconception that people on warfarin should avoid Vitamin K. Reducing your vitamin K intake can cause your INR to increase and may make it more difficult to control. Rather than avoiding vitamin K, you should maintain a consistent intake of vitamin K by maintaining a consistent diet. In other words, from week to week, you should eat the same types of foods.”

Nowhere does it say, never ingest vitamin K, you can never eat salad again, or kiss that calming cup of green tea goodbye. It is about consistency and slowly reintroducing vitamin K foods into your diet if you desire to and have previously eliminated them.

Yes, You Can and Should Consume Vitamin K

You do not have to avoid foods or other products that are high in vitamin K; these foods have many other vitamins and minerals that are part of a healthy diet, particularly when it comes to your heart. The most important thing to remember about vitamin K intake is being consistent as much as possible and communicating any changes that may occur.

But that’s Not What My Doctor Said

Unfortunately, I think it is easier for doctors to tell you to avoid vitamin K (and all of the wonderful, nutritious, satisfying foods that go with it) because it is just plain easier. This way, doctors can build a baseline for your warfarin dosing without having to worry about vitamin K obtained from foods and nutrients affecting your INR. Chances are you were not consuming green leafy vegetables on a consistent enough basis to include a vitamin K allowance in your treatment planning. Sure, we all enjoy a salad now and again or eat broccoli once in a while with dinner, but how many of us (truly, honestly, let’s stop kidding ourselves for one moment) could say without a doubt that we were eating three cups of spinach four days a week, a half a cup of broccoli or green beans two nights a week and scallions in our omelet every other Sunday? It’s difficult to say unless you are very conscious of it and most of us grossly underestimate the number of greens we actually consume, even though we should be consuming them frequently.

Almost Everyone I know who takes Warfarin Avoids Vitamin K

Not anymore. I remember the first time I posted that I was taking a vitamin K supplement in an online forum. It was in regards to a forum member’s frustration over her inability to maintain a therapeutic INR level. I posted- “I am taking warfarin and also vitamin K, both prescribed and monitored by my doctor. I started taking vitamin K after being on Arixtra injections [blood thinners that are injected into the stomach daily] for over ten months, which was concerning to my doctor because Arixtra is non-reversible [you cannot be given an anecdote to stop bleeding if you are seriously injured, for example in an accident] and there is not a lot of research about adverse effects to the body [beyond a typical-length pregnancy in which women are often put on injections to reduce the risk of clotting]. In light of some successful research, my doctor decided to actually put me on a low dosage of vitamin K to create a balance of warfarin and vitamin K in my blood. Within a month or so, my INR stabilized for the first time since leaving the hospital and I have not been on injections since. I also posted this link to some of the research that I could find myself.

I remember the first comment my reply received, “Sara, you need to get a new doctor pronto because yours will certainly kill you if you are taking vitamin K.” More of the like ensued and no one backed me up, leading me to believe I was alone in my treatment and my treatment’s success.

I was horrified. Since the beginning, I had trusted my doctor – he had after all found the Antiphospholipid Antibodies when the Emergency Room Doctors were all too hasty to send me away with three-month course of blood-thinning therapy blaming my DVT and severe PE on birth control and birth control alone. My case was so severe that a specialist was called in, my now hematologist, who I credit with saving my life and providing me with the ongoing care I so desperately need and will need from here on out. He had not yet steered me wrong. He explained what happened, my treatment, and what to expect in recovery when no one else had, not a single person.

There was no chance I doubted him on vitamin K. I kept up with my treatment. I ate greens about as consistently as I had – a few times a week and slowly increasing as I worked to get my diet and weight loss back on track. Through it all, I keep him informed of any major changes and continue to get my INR monitored at the least, bi-weekly.

What Should I Do?

Talk to your doctor. We need to be an advocate for our own health and we cannot let blood thinners determine how we choose to live our best lives.

Discuss incorporating vitamin K-rich foods back into your diet with your doctor; taking a supplement or alternative treatments (i.e. Xarelto) that do not affect vitamin K. Also discuss the implications of the absence of vitamin K in your body.

It is also important to keep in mind that other things impact the body’s vitamin K production and warfarin’s ability to metabolize including, but not limited to vitamins, nutritional supplements, antibiotics, bacteria/viruses, illness, and stress.


Share your Story. What are your thoughts on vitamin K and warfarin? Do you take or eat foods rich in vitamin K? Why or why not? What did your doctor tell you about vitamin K? Did you read the heart-healthy article? What are your thoughts on needing vitamin K?

There is hope for healing and you are not alone,



  1. My doctor told me that I could consume vitamin K, but it has to be on a consistent level and not just on fridays with fish as I had been doing. But as I don’t consistently eat vitamin K foods, I’ve eliminated them for the moment. I had my P.E. a month ago, and so am really new to this whole situation. I really miss green tea with mint, and coriander, and have an appointment with a dietician in the next week or so. I will ask her how to introduce vitamin K at safe levels into my diet without throwing my INR completely out of whack!

    • Thanks so much for stopping by and sharing your thoughts on vitamin K. Best of luck to you when you speak to your doctor. I think talking to a dietician might be very helpful! I have not been drinking Green Tea regularly and I also miss it. I hope you have an uneventful recovery and best wishes to you.

  2. I have had 2 DVTs, one in 10/2012 and another 11/2013. As a 21 year old nutrition student, the first thing that came to mind once starting Warfarin: How will this change what I eat?
    I did so much research on my own and also consulted my professors, who are Registered Dietitians (along with my doctor of course). I learned quite early on that I need to make my Vitamin K intake consistent. I began meal planning, making sure that my portion sizes were pretty equal all of the time (small salad, 1/2 cup green beans/broccoli, 8oz green tea etc.).
    When you can get your intake under control (for the most part, we are all human and are bound to mess up now and then) then you will see your INR staying consistent. Its important to have regular appointment with your INR nurses, especially if you are going to start adding more vit K into your diet! Their job is to adjust your dosage to accommodate your diet as well (this is why consistency is SO important).

    Another SUPER important reason you should be getting foods with vit K into your diet (other than the fact that you need some for your body to properly function): Those foods are almost always packed with other awesome nutrients!! Vitamin C, Iron, Vitamin A, Vitamin E, folate, proteins and so much more.

    If you are completely avoiding vit K with the fear of doing something wrong, I completely understand. If you haven’t already, speak to your doctor regarding your diet and how you should/could change it, also Dietitian services are usually covered by insurance and they would be able to give you meal plans and ideas to make sure you are getting the appropriate nutrients!

    • Hi Michelle! Thank you so much for your thoughts on Vitamin K and warfarin. As a nutrition student, I find your input very valuable, and I hope others in this community will as well.

      As I am sure you know, it is a common and concerning misconception that we should avoid such a vital nutrient as Vitamin K, which as you mentioned, could also lead to us not getting other important nutrients as well.

      Thank you for noting the fear some people may feel after possibly being told to avoid Vitamin K at the start of their treatment. Your advice is spot-on and I appreciate it greatly.

      Thank you so much, Michelle!

  3. heather says

    I too have aps and lupus anticoagulant. Im a lifer on warfarin as well. Suffered several mini strokes and only 33 years old. I have found a routine that allows me to still consume my green tea, broccoli and “daily salads” and I still stay therapuetic through all the greens 🙂 doctors advise against it but I dont believe any vitamin or nutrient should be left out of your diet due to a medication. If u r thinking about adding back in ild fefinitly tell your doctor his permission or not u r going through with adding greens back into your diet and will need to be tested weekly again until your inr stabalizes in its therapuetic range. Whatever u do add it in 1 thing a week just dont do all at once as it can cause ur inr to drop significantly. Good luck. Just remember the doctor works for us we dont work for them. Therefore they should listen to your comcerns and work around what best suites u

    • Hi Heather! Welcome. Thank you so much for sharing your thoughts on this. I am so glad to hear I am not the only one with APS, on warfarin and maintaining a consistent diet WITH essential nutrients such as Vitamin K. I am 31. I have not suffered a stroke, but I am constantly concerned about that with APS. It always feels positive to be validated and thank you for doing that for me personally this evening. I am glad to be able to connect with you. I appreciate your advice on incorporating these foods back into the diet and know it is beneficial for this community.

  4. Nicole S. says

    Finally an article on this issue that makes sense and puts my mind at ease! Diagnosed with my first (and hopefully last) DVT a few weeks ago, and I’m working on keeping my diet consistent. The husband and I were discussing how stupid it was that medical professionals are/were telling their patients to just avoid vitamin K. “Here, take this medication for the rest of your life and also, don’t eat vegetables that are good for you ever again! Have a nice life!” The thought of it makes me steamin’ mad! So anyway, thank you!

    • You’re welcome, Nicole and thank you for stopping by! I agree with you – I do not know why they tell us not to eat K because it JUST DOES NOT MAKE SENSE, as you know. I am glad to hear someone else shares the same sentiment and is trying to keep it consistent – by not avoiding it, but actually eating it. I wish you the best in your recovery. And, P.S. – it makes me steamin’ mad too!! Thanks for reading.

  5. I have the same blood condition I also have a back condition where I take pain medication I was taking mussel relaxing tabloid but I was told I could not take them any more so I am now in a lot of pain.
    Do you know of any medication I could take that would do the same as the mussel tablit was doing

    • Hi Carol. Thank you for your question. I do not as I am not on pain medication and do not take anything other than Tylenol (if I have a bad headache or can’t sleep at all). Have you thought of seeing a pain specialist? I am so sorry to hear you are in pain. Wishing you relief and comfort.

  6. Damaris Abreu says

    I was diagnosed last year with Antiphosolipid Syndrome. I also has a blood clot in my left kidney. My doctor doesn’t want me eating anything that has vitamin k. I also have iron deficiency anemia. I feel like I’m on a roller coaster waiting to fall off. I don’t know many people with this disease. If you can help I would love it. Thanks

  7. May I ask a question? Do I need to keep my daily intake of vit K constant, or total weekly intake? The studies (pub med) I’ve found write about weekly intake, but maybe that one cup of spinach per week and little in between is too infrequent. I’d really like to know as my INR’s are consistenly low of late and I wonder if it is the shift from summer salads to winter greens. I don’t eat them every day, but certainly consistently every week. BTW here also an APS Lupus sufferer with 2 CVA’s, 6 TIA’S and 9 pregnancy losses so far….

  8. LeRoy H. Rahe, Jr. says

    The problem here is: blood clot patients hear their doctor bring up the vitamin K issue. If you are the normal person (patient) you have never heard of vitamin K before). I had my first clot in 1992, then seven more clots (with numerous T.I.A.’s in between) and another stroke thrown in for good measure. My first neurologist told me to avoid Brussels sprouts. He didn’t say why. Since then I have become well educated in vitamin K usage. It IS a necessary vitamin to promote overall good health. I thing that I have deducted over the past 24 years is that there is more of a concentration of vitamin K in the ” darker” color green veggies than in iceberg lettuce. Don’t avoid them (Broccoli, Brussels Sprouts, Collard Greens, Kale, Lettuce, Mustard Greens, Spinach and Turnip Greens) but, eat them in moderation and on a regular basis. I hope this helps! LHR

  9. Joseph C. McNeely says

    Don’t Mattet To Any Family Members At All… Clots.. Warafine….The Cold…Or Anything….

  10. Jackie McGraw says

    Hello. I am 60. Had my stroke at 40. Diagnosed 20 years ago with SLE (anticardiolipin antibody disorder, ‘lupus of the blood’) and on warfarin since. Was healthy and athletic before then. I too bought into the ‘no Vitamin K’ scene. I now have fibromyalgia (10 years), cancer x3, complete hysterectomy (cancer), huge weight gain, brain aneurism, pulminary embolism, skin rash and probably something else I’m fogging on. However my daughter researched more than I did after a breast cancer operation in 2013 and moved right in for 3 months to feed me into recovery. A certain amount of vitamin K (1c spinach) every day in my smoothie along with many other seeds, anti-oxidants, fruits, etc… OR 2c of romaine, etc…(90 mcg vitamin k per day for women on warfarin, 120 mcg for men). EVERY DAY! I literally skipped and danced my way through my 25 sessions of radiation 3 months later. Felt great. Today I feel great and my new Doctor is on board with anything I want to do to better my life (researched of course and within reason) while being monitored. We are indeed what we eat. Thanks for sharing this very important misconception about warfarin and vitamin K. The key is being consistent. Wish I started 20 years ago!

  11. I’ve had APS for over 20 years with only taking aspirin until I recently passed out due to multiple PEs & now take Warfarin & a baby aspirin daily. When first told in the hospital about vitamin K & Warfarin interaction, I had a literal panic attack because I only eat protein & green vegetables. My doctor said I could continue eating that way & he’d medicate me for it. So, I’ve continued to daily eat a large mixed greens salad & drink 32 oz of weak strength green tea. My (mostly) stable INR Warfarin dose is 12.5mg for 2 days & 10mg for 1 day which seems high compared to what I read of other people’s doses. I love my salads & green tea & my doctor says I’m fine with what I’m doing but I often wonder if it’s bad for me to take such a high dose of Warfarin for life.

  12. I hav dvt in my right leg plz suggested me some good health tips and also about vitamin k benifit or problem.

  13. Hi all,
    Heart attack in 2000 at age 30yo. Just said a clot, arteries were clear. I had other issues going on, went from doctor to doctor. There is nothing wrong. Then I got diagnosed with RA. In 07, ended up in hospital by way of emergency for 2 months. [50 days in ICU, 10 on floor. Then in 08 got diagnosed by a wonderful Dr at MUSC. She did comprehensive history, and put all things together. Lupus along with anti-phospholipid blood clotting disorder/ heart attack.
    I take warfarin and they did say keep diet consistent. But other doctors I see will pipe up, or people or just regular people will tell you NO VITAMIN K. Many doctors think we are stupid. We can not handle managing our medicine or our condition or whatever. It kills me and I advocate all the time for people to push their doctor or find another one. I am in charge of my body and I don’t want to ever be in an ICU at deaths door again. I saw a doctor 3 days before I ended up in ICU in 07.


  1. […] might start talking about it, talking to others, making necessary and consistent modifications to your diet, increasing your fluid intake and maybe even beginning an exercise program. Recovery is different […]

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