I don’t know how long I have been in kidney failure. My doctor did a Cystatin C test last year and it showed that I was in stage 3. I had no clue that I had this problem. I already had a good diet, but did not pay much attention to phosphorus and potassium. I only eat once a day, at noontime, so I don’t eat a lot of proteins and I have always avoided sodium because of my coronary artery disease.