Oxalate
Label Mnemonic: OXALU
Epic Lab Code: LAB421
Downtime Form: A-1a Miscellaneous Request
Commercial Mail-out Laboratory
5231 RCP
356-8593
Specimen(s):
Specimen Instructions:
Patient should avoid ingestion of vitamin C prior to collection.

Refrigerate during collection in plastic container. 24 hr specimen must reach Core Laboratory with 24 hrs of finishing collection. Submit dates and times of collection on requisition.
Collection Medium:
Urine - 24 hour/timed plastic urine container
Minimum:
Preferred Minimum: 4.0 mL of well mixed 24 hr urine sample. Refrigerate during collection and submission to lab.
Rejection Criteria:
Urines not refrigerated during collection.
Delivery Instructions:
Submit refrigerated specimen to laboratory as soon as possible after collection period is completed. CRITICAL FROZEN.
Turn Around Time:
1-4 days upon receipt in reference laboratory
Reference Range:
Components Reference Interval Creatinine) Male (24-hours) 3-8 years: 140-700 mg/d 9-12 years: 300-1300 mg/d 13-17 years: 500-2300 mg/d 18-50 years: 1000-2500 mg/d 51-80 years: 800-2100 mg/d 81 years and older: 600-2000 mg/d Female 3-8 years: 140-700 mg/d 9-12 years: 300-1300 mg/d 13-17 years: 400-1600 mg/d 18-50 years: 700-1600 mg/d 51-80 years: 500-1400 mg/d 81 years and older: 400-1300 mg/d Oxalate, Urine Male (24 hours) 0-12 years: 7-31 mg/d 13 years and older: 16-49 mg/d Female 0-12 years: 7-31 mg/d 13 years and older: 13-40 mg/d
Interpretive Data:
Reference intervals for random urine samples (mg/L) are not available.
Comments:
Vitamin C (ascorbic acid) quickly degrades to oxalate in non-acidified urine. Patients should discontinue use of vitamin C supplements at least 48 hours prior to the start of urine collection and abstain until collection is complete.

Preservation with Sulfamic Acid before transporting is highly recommended.
Methodology:
Quantitative Spectrophotometry
CPT Code:
83945