I am on Coumadin also. The only foods I have heard about interfering with blood thinners is leafy green vegetables of all kinds, from spinach and kale to arugula and green leaf lettuce, are especially rich in the vitamin. In plants, vitamin K is involved in photosynthesis, so an easy rule of thumb is the greener the leaf, the more vitamin K it contains. Spinach has a lot, for example; pale iceberg lettuce much less. Vitamin K is also abundant in many vegetable oils, including soybean, canola, and olive oil. Click this link for more info: http://www.webmd.com/food-recipes/features/featured-nutrient-vitamin-k