Oxalate/Creatinine Ratio, Urine
Use
Calculating the oxalate concentration per creatinine; used to assess urinary oxalate excretion that may indicate primary hyperoxaluria, secondary hyperoxaluria due to fat malabsorption, idiopathic hyperoxaluria, or high dietary intake of oxalate or vitamin C. Elevated urinary oxalate is associated with calcium oxalate kidney stone formation. Urinary oxalate-to-creatinine ratio varies by age in children (for example, <0.175 mg/mg at birth, decreasing to <0.048 mg/mg by adolescence).
Special Instructions
Only orderable as part of a profile (see ROXUR / Oxalate, Random, Urine). The test is a calculated ratio performed in software (“Soft”).
Limitations
No established reference values; ingestion of ascorbic acid (>2 g/day) may falsely elevate measured urinary oxalate excretion. All specimens are evaluated at Mayo Clinic Laboratories for test suitability.
New York Approved
Methodology
Other
Biomarkers
LOINC Codes
- 13483-3
- 13483-3
Result Turnaround Time
3 days
Related Documents
For more information, please review the documents below
Specimen
Urine
Volume
Not provided
Minimum Volume
1 mL
Collection Instructions
Only orderable as part of a profile (see ROXUR / Oxalate, Random, Urine).
Causes for Rejection
All specimens will be evaluated at Mayo Clinic Laboratories for test suitability.
Stability Requirements
| Temperature | Period |
|---|---|
| Room Temperature | 72 hours |
| Refrigerated | 14 days |
| Frozen | 14 days |