Do you have a preferential 24-hour urine lab test between urine urea nitrogen, urine protein catabolic rate, and urine sulfate when evaluating a recurrent calcium based stone former who has hypercalciuria presumed secondary to excess animal protein intake?

No. I refer most of my stone patients to the stone clinic dietitian who takes an accurate history of dietary nutrient intakes, including protein, and makes recommendations accordingly.

Stephen B. Erickson, MD

Urine urea nitrogen and urine protein catabolic rate are functionally equivalent measures of protein intake (simple calculation to convert urea to protein catabolic rate). The generally accepted protein catabolic rate target is 0.8 - 1.0 g/Kg, though I do subjectively adjust my patient goals for body type. Protein intake is necessary to maintain muscle mass, not fat, and the target above is based on lean body mass. While beef intake is nominally higher risk than chicken or fish, I generally plac...