My eGFR was only 43 and I read Dr. Hoffer's article on Niacin he recommended to his patients taking 3 gms a day, I took it in 3 dosages a day and my last blood test shown my eGFR was 47 and seems to be working in my case. But taking 1000mg after each meal gave me uneasy feeling and I wonder if I could sustain that any more.