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.

Resources

• Vitamin K and Warfarin – What You Should Know (article via Clot Connect)

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,