Instructed about diet as a major factor that can affect the stability of your Coumadin level. Explained about Vitamin K and its importance for blood to clot and why it's important in patients taking Coumadin, because high amounts of Vitamin K (e.g.green and leafy vegetables like lettuce, spinach and broccoli)can work against the drug. Instructed patient to eat what he normally eats just as long as he's consistent with his vitamin K foods. Verbalized understanding.