Warfarin diet – what foods should I eat if I am taking warfarin?
A warfarin diet is very important because certain foods and beverages may interact with warfarin. People often get very confused about the information presented to them. It is understood that avoiding large amounts of vitamin K is important, but what foods are high in vitamin K? And how does vitamin K impact on warfarin?
What is warfarin?
Warfarin, also known as Coumadin, is a type of anti-clotting medicine called an anticoagulant. It is used by people to help prevent blood clots. Regular blood tests are needed to make sure that your INR is within the target range.
INR (International Normalised Ratio) is a type of test used to determine the effects of the warfarin. Basically it measures how long it takes for the blood to clot. The higher the INR, the longer it takes for the blood to clot and the bigger the risk of bleeding. On the other hand, the lower the INR the more likely you are to develop a blood clot. The target INR is usually around 2-3 however this can vary between people.
Warfarin and diet. How does diet play a role?
Vitamin K has the opposite effect to warfarin, meaning that it helps the body to create blood clots. For this reason foods that are high in vitamin K need to be monitored. This means that eating for warfarin is very important.
What foods are high in vitamin K?
The following table is adapted from NPS Medicine and shows foods that are high in vitamin K
Should foods with vitamin K be eaten as part of a warfarin diet?
YES! Vitamin K is important for health and needs to be included within the diet. However, eating an appropriate diet which provides a CONSISTENT amount of vitamin K is needed to make sure that INR stays stable. Whenever making changes to your diet, you should inform your local doctor as extra blood tests may need to be performed.
Warfarin diet summary
It’s important to be consistent in how much vitamin K you get daily by making sure you have an appropriate warfarin diet. The Adequate Intake (AI) for Vitamin K for males is 70µg/day and for females is 60µg/day. Eating small amounts of foods that are rich in vitamin K shouldn’t cause a problem. You should, however, avoid eating large amounts of foods which are high in vitamin K as shown in the above table.
Certain drinks can increase the effect of warfarin, leading to bleeding problems. Avoid or drink only small amounts of alcohol when taking warfarin. Drinking large amounts of cranberry juice can also increase the risk of bleeding in some people taking warfarin, however according to the NPS website drinking 250ml or less of cranberry juice is unlikely to affect the INR.Of course, if you have any concerns, you should always talk to your local doctor.
If you have questions about an appropriate warfarin diet or for a personalised meal plan, contact your local doctor who will arrange for you to see a dietitian in Sydney. Contact us today!
This article was written by our nutritionist Rhiannon Welsh who is a Dietitians Association of Australia member and Accredited Practising Dietitian.
For more information about warfarin see the NPS website, click here.