Expert: Sarah A. Allen, MS, RD - 9/16/2009

Question
My wife has had heart valve replacement surgery and now has 2 mechanical valves. She is trying to regulate her vitamin K intake because she takes Warfarin to control her INR (blood clotting factor). We have found an excellent American website (USDA National Nutrition Database) which gives vitamin K content for typical portions of many common foodstuffs but it is silent about offal, I presume because Americans don`t eat it. She likes to eat lambs liver and kidneys and would like to know where this would lie on a scale for vitamin K content where green leaf vegetables are at the high end and lean ham at the low end. Which common foodstuff would be similar in vitamin K concentration to offal. Many thanks for any help you can give . Regards Colin.

Answer
Hi Colin!  You are correct, offal is not a very popular food in the United States.  (Actually, I had to look up what it is!)  We do eat liver, but that's about the extent of most Americans' experience with organ meats.  I was able to find some vitamin K information for you.  Liver is right up there with leafy greens as a high vitamin K food.  Kidneys were listed as a good source for protein, iron, phosphorous, vitamin A, thiamine, and riboflavin and seem to be more comparable in vitamin K content to steak.  The good news about the liver, however, is the most important part of vitamin K with warfarin is to be consistent in the amount eaten.  If your wife has a small serving of a high vitamin K food every-other-day or twice-a-week, that should be fine.  What she wouldn't want to do is go for a longer-term consistency, such as once-a-week or once-a-month, because the idea is to keep the level of vitamin K in the body consistent so medications can be altered if necessary.  Most people think they have to give up all foods with high levels of vitamin K forever, but that's usually not necessary.  If you have questions about vitamin K consumption more specific with your wife's warfarin dosage or health condition, please speak with the doctor.  I wish you both all the best!