It's easy to get answers about health and nutrition! Just send your question by email to [email protected] and Dr. Harlan will respond to selected questions of general interest. Answers will be posted in the Ask Dr. Gourmet newsletter (sign up now!) and archived in the Ask Dr. Gourmet section of the website.
When the doctor put me on warfarin some years back, he told me to avoid eating broccoli, spinach, cabbage, etc., because of their high Vitamin K content. Then I found out from random reading that lots of other foods besides green leafy veggies contain Vitamin K. So I was very pleased, a year or two ago, to find your book, VITAMIN K LEVELS IN COMMON FOODS (PDF). It has been really helpful!
But I have a question about information on page 50. It lists various kinds of pie, and indicates that most of them (except blueberry) contain very little Vitamin K. But under "Pie crust," it gives Vitamin K content of 10.3 for "Pie crust, standard-type, frozen, ready-to-bake, baked" and 26.6 for "Pie crust, standard-type, prepared from recipe, baked."
Is that a contradiction? How can pie contain very little while pie crust contains a lot more Vitamin K? What ingredient in pie crust has Vitamin K?
The issue appears to lie in the portion size of pie crusts as reported in the source database. Our book reports on single portion sizes, but relies on the USDA database (the industry standard) for its information. I checked the database at the USDA site and found that the listing for "Pie crust, standard-type, prepared from recipe, baked" is indeed 26.6 micrograms of Vitamin K - for the entire pie (8 servings). One serving of that pie crust is 3.4 micrograms of Vitamin K.
I checked other variations of the pie crusts listed and the issue is the same - the Nutrition Information is for the entire crust and not a single slice (1/8 pie).
Unfortunately, the USDA does not specify the ingredients used in these crusts so I can't be certain what would be the source of Vitamin K. The good news is that a single slice of pie crust - just the crust - is safe for Coumadin users. The USDA gives the following amounts of Vitamin K for a single slice of the following types of pies made from a generic recipe.
Blueberry Pie - 13.1 mcg
Cherry Pie - 9.5
Pecan Pie - 20.6
Pumpkin Pie - 17.6
Lemon Meringue - 2.4 mcg
Note that your pie recipe may not be the same! To analyze your own recipes, for pie or for anything else, you can use the USDA Supertracker until June 30, 2018, when it will be discontinued. If you know of another free online recipe analysis site that includes Vitamin K content (many only create a standard Nutrition Information box), please comment and let us know about it.
Thanks for writing,
Timothy S. Harlan, MD, FACP, CCMS