Patient Preparation: Patient should avoid ingestion of vitamin C prior to collection.
Collect: 24-hour urine. Refrigerate during collection.
Thoroughly mix entire collection (24-hour) in one container. Do not exceed 4 mL in Tubes.
Preserved: Transfer 4 mL (1.5 mL minimum) aliquot to a Transport Tube with Sulfamic Acid. Mix well. Freeze immediately.
Unpreserved: Transport a 4 mL (1.5 mL minimum) unadjusted aliquot of urine to an ARUP Standard Transport Tube. Freeze immediately.
Record total volume and collection time interval on transport tube and test request form.
CRITICAL FROZEN: Separate specimens must be submitted when multiple tests are ordered.
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