Warfarin, your diet, and vitamin K foods

What do I need to know about my diet?

Some foods you eat affect the way warfarin works in your body. Try and keep eating what you normally do. It is most important to eat a healthy, consistent, and balanced diet.

Certain foods and dietary supplements have vitamin K. Vitamin K works against warfarin.

• If you eat more vitamin K, it can lower your INR. This puts you at a higher risk for making a blood clot.
• If you eat less vitamin K, it can raise your INR. This puts you at a higher risk for bleeding.

Important things to know about vitamin K are:

• It is okay to eat foods that have vitamin K. Make sure it is not in large amounts.
• It is important to eat the same amount of foods that have vitamin K each week.
• Check with your care team before making any big changes in your diet.
• Contact your care team if there are sudden changes in your diet due to illness.

What foods are high in vitamin K?

The most common foods with high vitamin K are green leafy vegetables, such as:

• Kale
• Collard or mustard greens
• Broccoli
• Spinach
• Cabbage
• Romaine or dark green lettuce

Foods with vitamin K that could affect warfarin are listed on the next 2 pages. 

Other foods that could affect warfarin are beef liver or other animal liver products.

Vitamin K can also be found in some nutrition supplements, such as:

• Boost^®, Ensure^®, and Slim Fast^®
• Certain multiple vitamins and Viactiv^® calcium chews
• Tobacco, such as cigarettes and chewing tobacco

Talk with your care team if you have questions about vitamin K.

Vitamin K foods

Here is a list of some common foods that have vitamin K. It is best to eat the same amount of foods with vitamin K each week. Ask your care team if you have questions about other foods.

Very high in vitamin K (more than 800 mcg or micrograms per serving)

High in vitamin K (400 to 800 mcg per serving)

Medium in vitamin K (80 to 400 mcg per serving)

Tables were adapted from the USDA (United States Department of Agriculture) National Nutrient database for Standard Reference.