@like2dance2 have you had a Cystatin C done for the alternative version of the GFR? My creatinine-based GFR also dropped precipitously in a few months but I was told the Cystatin C is more accurate and that was much better (stage 3a). Apparently creatinine is affected by othe factors. Just a thought.

Also do you think any meds or even vitamins could be a factor? I had to stop taking some meds for pain (flurbiprofen).