24-Hour Urine Phosphorus Test

This quantitative laboratory test measures the excretion of phosphorus (as inorganic phosphate) in a 24-hour urine collection. It reflects the balance between dietary phosphorus intake, intestinal absorption, and renal excretion. It is an important tool for assessing disorders of bone and mineral metabolism, particularly in cases of hypercalcemia or hyperphosphorusemia, or for evaluating renal retention.