Hi, I am a female, 87 yrs old, I have a thyroid condition, about 6 yrs ago, I got AFib, I am on warfarin . I had to change to another doctor as my great doctor went into teaching other want to be doctors. I m having a hard time adjusting my blood, I take my own blood every Monday, give the reading results to this new doctor, but, for some reason he is always adjusting the dosage. How much of vit. K can I eat a day? My blood flucturates from high to low.