Test Overview
Test Methodology


Test Usage

Renal function test, evaluate calcium/phosphorus balance. Normal phosphate excretion reflects the dietary intake of phosphate. The excretion varies with growth, dietary intake, renal function, muscle mass and hormonal activity. Urinary phosphate excretion will be decreased in hyperthyroidism.

Reference Range *

400 - 1200 mg/TV (24 hour collection). Random urine collections vary with dietary intake and are dependent on diurnal variation, and are reported in units of mg/dL, for which reference values are not established.

Test Details
Days Set Up
Analytic Time

8 hours

Soft Order Code
MiChart Code
Phosphorus, Random Urine
Chemical Pathology
Specimen Requirements
Collection Instructions

Collect 24 hour urine specimen with no preservative. Aliquot 5 mL into a plastic urine container and refrigerate. Record total 24 hour urine volume and collection dates/times on request form. Random urine also acceptable.

Alternate Specimen
Specimens collected with glacial acetic acid or HCl preservative are acceptable. If collected in container with acid preservative, indicate on container and requisition: "Collected in Acid".
Normal Volume
5 mL aliquot of 24 hour urine collection or 2 mL aliquot of random urine collection.
Minimum Volume
2 mL aliquot of 24 hour urine collection or 1 mL aliquot of random urine collection.
Rejection Criteria
Diapers, sections of diapers, swabs or any other absorbent material will not be accepted as a collection container for urine.
CPT Code
Fee Code
PHOSU 2778-9 PHOSQ 2779-7
NY State Approved