Again I always thought the beginnings of stage 3 were essentially normal over a certain age. I never worried about GFR's in the low 50's but a dip to 36 along with high antibodies for scleroderma sent me to a nephrologist.

I learned that the issue of diet is more complicated than we think. I wrote this before and I will write it again: I was told to have more salt (low blood pressure can affect GFR) and more protein (for muscles, since loss can also affect GFR). Other kidney patients are told the opposite. I also had an echocardiogram to make sure a low ejection fraction was not a factor.

Maybe it is wise to have a full workup like that before embarking on what is considered the standard "renal diet." And if we have GFR's in the 50's or even higher 40's and no protein in urine, maybe we can eat a normal diet and consider changes if things get worse. And the Cystatin C may be much better than the GFR based on creatinine!