I believe that a good diet is better than most nutrition supplements which are expensive and not of much proven benefit, except if there is malnutrition and certain dietary deficiencies.
If any such drugs are taken, it is advisable to check Prothrombin Time with INR. Warfarin dose may need adjustment depending on the INR value. Warfarin is a drug to prevent blood clotting in the valve and to prevent the valve from becoming 'stuck'. Depending on the type of valve and other clinical parameters, INR value should be maintained between 2.5 and 3.5. Too high a dose of warfarin can cause bleeding while too less a dose can cause blood clotting. Optimum dose is not fixed and can vary depending on the patient, diet, other medicines, etc. Remember to take the drug at least 2 hours after any food and not take anything further for another 2 hours after the medicine