According to the FDA, some studies have found D-ribose supplementation causes an increase in uric acid. High uric acid levels (hyperuricemia) may not cause significant adverse effects in most people however some may develop gout, kidney stones, or kidney failure resulting from high uric acid levels. As kidney function declines and large amounts of proteins are passing into the urine, swelling of the hands, feet, abdomen and face may occur.
The stages of CKD (Chronic Kidney Disease) are mainly based on measured or estimated GFR (Glomerular Filtration Rate).
Stage 1 (90+)
Normal kidney function but urine findings or structural abnormalities or genetic trait point to kidney disease
Stage 2 (60-89)
Mildly reduced kidney function, and other findings (as for stage 1) point to kidney disease.
3A (45 - 59) 3B (30 - 44)
Moderately reduced kidney function.
Stage 4 (15-29)
Severely reduced kidney function. Planning for endstage renal failure.
Stage 5 <15 or on dialysis
Very severe, or endstage kidney failure (sometimes call established renal failure)