Ask Dr. Gourmet

Should Coumadin (warfarin) users peel zucchini?

My husband is on Coumadin (warfarin) and his reading this past week was below the 2.0. He was told not to eat any green leafy vegetables and when I asked about zucchini I was told I would have to peel it. I had never heard or read about that before. His diet for the next 7 days is to be limited to non-green veggies but he could have one serving of green vegetables during that 7 day period.

Where can I find research on this? Especially interested in zucchini because I buy that all year long and cook it along with eggplant, etc.

Dr. Gourmet Says...

I am not sure why your husband’s physician might have suggested peeling the zucchini.

Zucchini and other squash varieties are low in Vitamin K. Eight ounces of zucchini, including the peel, contain only 9.8 micrograms of Vitamin K. This is a medium sized zucchini and should be safe for those on Coumadin (warfarin).

It is a common misconception that all green vegetables are high in Vitamin K. The most challenging vegetables will be the cruciferous variety — cabbages, levy greens and broccoli.

You can track the amount of Vitamin K in any food using the USDA database at this link:

http://ndb.nal.usda.gov/ndb/foods

Thanks for writing,

Timothy S. Harlan, MD, FACP, CCMS
Dr. Gourmet