Coumadin is prescribed to prevent blood clots and increase the amount of time it takes your blood to form a clot. This allows the blood to flow more easily through narrowed blood vessels.
You should have a consistent intake of vitamin K (Recommended Dietary Allowance for men is 120 micrograms, women 90 micrograms per day). Avoid supplements with vitamin K as that would interfere with the amount of Coumadin needed to regulate your clotting time. Your clotting time will be periodically tested by your doctor to regulate this medication.
Foods high in vitamin K are green leafy vegetables (kale, collards, spinach, turnip greens, beet greens, mustard greens, dandelion greens), Brussels sprouts, broccoli, green onions, parsley, asparagus, sauerkraut and lettuce (endive and green leaf). Milk, meat, eggs, and cereal contain small amounts. Vitamin K content in vegetables and fruits vary. See table for a list of foods with vitamin K because vitamin K content of food is not usually listed on food labels. Vitamin supplements containing vitamin K are available by prescription.