Vitamin K1, found in many foods, is the problem. You are taking an anti-coagulant – Warfarin. Vitamin K1 is a coagulant. Therefore, one works against the other. The foods usually considered highest in Vitamin K1 are kale, spinach, broccoli, brussels sprouts, cabbage, collard greens (leafy fresh herbs), mustard greens, Swiss chard and most lettuces. However, in the Medical News Today, 12 February 2019, the American Heart Association added amaranth leaves, asparagus, endive, cress, green kiwi fruit, soybeans, tuna fish in oil, turnips and vegetable drinks to this list. Green tea and alcohol are also of concern.
There are two ways of managing your Vitamin K1 consumption:
‘dose to the diet’ – This means that you eat what you want, when you want, and the doctor will prescribe more medication to balance your INR. This is the most common approach in North America and some other countries.
‘diet to your dose’ – This means that you eat a consistent amount of Vitamin K1 daily so that your INR levels and your dose of Warfarin, can be stabilised. This is the recommended method of control from the manufacturers of Warfarin, Coumadin and Jantoven and from groups such as the Mayo Clinic and the University of Iowa Hospitals and Clinics in the USA, the Governments of Canada, Australia and many other countries.