Vitamin K is a one of the essential vitamins found in a healthy balanced diet. Your liver uses vitamin K to produce clotting factors, and as such plays a role in your body's natural clotting process. Warfarin works against vitamin K and reduces the amount of clotting factors your liver can produce.

Vitamin K is found in some of the foods that we eat, so our diet plays a big part in how much vitamin K is in our body. Changes in the amount of vitamin K in your body will mean that your body needs different amounts of warfarin to have the same effect on your clotting factors. For example, if you reduce the amount of vitamin K you eat, you will have less in your body for warfarin to work against, so even less clotting factors will be made and your INR will increase.

The foods you eat can affect how well warfarin works for you. It is important to be aware that changes in diet can affect your warfarin therapy. The most important thing to remember is to eat what you normally eat and not make any major changes in your diet without talking to your doctor.

Vitamin K is essential for a healthy diet so you should not try and eliminate vitamin K from your food intake. The recommended daily intake of vitamin K is the same for people who take warfarin and for those who don't.

The aim is to balance your vitamin K intake by being consistent with the foods that you eat.