Important Nutrition Tips If You Are Taking Warfarin (Coumadin)

Important Nutrition Tips If You Are Taking Warfarin (Coumadin)

Did your doctor recently prescribed you Warfarin (Coumadin)? Are you interested in learning more about how this drug interacts with the foods you eat? You’ve come to the right place!

In this video, Amanda Haney will talk about how your diet affects Warfarin and what you can do to ensure your medication is working properly.

If you don’t like the video or want more information, continue reading.

What is Warfarin?

Warfarin is a medication given to individuals who have an increased risk for forming blood clots. Certain medical conditions can increase your risk for blood clots. As a result, Warfarin works to prevent blood clot formation and reduce your risk for heart attack, stroke, or other serious complications.

When your body senses an injury, a series of reactions occur to form a blood clot that can protect the injured area. Vitamin K is one of the substances in your blood that is required for these reactions to occur.

Warfarin works by slowing the activity of Vitamin K to slow blood clot formation. Therefore, when you are taking Warfarin, it is important that you keep your Vitamin K intake consistent. When people hear this fact, the most common response I see is they cut Vitamin K foods completely. This is not necessary, so let me explain.

RELATED: Dietary vs Blood Cholesterol: What’s the Difference?

Broccoli has vitamin k

Warfarin and Vitamin K

Your doctor will measure your blood clotting time before you start this medication. This measurement helps the doctor determine the medication dose that is right for you, then your doctor will continue to monitor your levels to make sure your clotting time remains in a healthy range. If you change the amount of Vitamin K you are eating after you start the medication, you can affect your blood clotting time.

Greatly increasing your Vitamin K intake decreases the effectiveness of your medication. As a result, you’ll remain at an increased risk of forming blood clots. On the other hand, if you greatly decrease your Vitamin K intake, you’ll increase the effectiveness of your medication. This is dangerous because your blood can become too thin, putting you at an increased risk for bleeding.

The major takeaway here is, in order for Warfarin to be effective, you must keep your dietary consumption of Vitamin K consistent!

RELATED: A Complete Overview of the New FDA Nutrition Facts Food Label

Spinach has a lot of vitamin k

Foods that contain Vitamin K

Lastly, you may be wondering what foods contain Vitamin K.

The greatest source of Vitamin K come from green leafy vegetables like kale, spinach, swiss chard, and collard greens. Other common foods with less Vitamin K are broccoli, cabbage, other lettuces, asparagus, avocado, tuna, blue or blackberries, and peas.

These foods are packed with important nutrients, so it is important that you keep them part of your healthy diet!

RELATED: Fat Facts: The Good, the Bad, and the Truth


In the end, I recommend working closely with your registered dietitian and doctor while taking Warfarin. Whether you are interested in increasing your Vitamin K rich foods or if you are having trouble maintaining your blood clotting time in a healthy range, your medical team can help you determine a meal plan that is right for you!

Previous articleSilver Diamine Fluoride (SDF): What You Need To Know
Next articleThe Importance of Oral Hygiene During Childhood
Amanda Haney, MS, RD, CNSC
Hi, my name is Amanda Haney. I am a registered dietitian, board-certified nutrition support clinician, Cal State Long Beach alumnae, and former pediatric clinical dietitian. Currently, I am working as a project manager at Children’s Hospital Los Angeles. As a clinical dietitian or in my current role, my passion is working in a diverse setting with a variety of teams in order to improve patient outcomes and achieve better health for the families in my community. I became a dietitian because I love food and I love medicine. There is so much misinformation about nutrition in the media, so I enjoy creating educational content that makes nutrition simple and to make your health goals achievable. In my free time, I love soaking up the beauty at the beach, riding my bike, staying active, cooking, and, most of all, spending time with my family and friends!


  1. hi, nice to meet and hear from you. I am currently a patient under treatment for DVT causes. I thank you for your fruitful video. the main reason I am writing to you is simply that I did not get any information or advice from my personal doctor for my diets. maybe for many possible reasons which I think I get to know later. for the time being what matters most is my health. I would be so thankful to you if you could be more available to give me advice about my nutrition. thanking you before