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The mean urinary citrate excretion rate in patients with idiopathic calcium urolithiasis has been found to be significantly lower than that of control groups. Hypocitraturia is common in patients with urolithiasis resulting from renal tubular acidosis and in patients with enteric hyperoxaluria. Citrate excretion is low in renal insufficiency.

Specimen Type: 24 Hour Urine

Collection Container: 24 Hour Plastic Urine Container

Desired Specimen Volume: 2 mL

1. Collect a 24-hour urine collection in a timed collection kit.
2. Specimen must be collected in a plastic container and refrigerated during collection.

1. Mix well and transfer 2 mL of urine to a LabCorp pp transpak frozen purple tube and freeze immediately.
2. If specimen cannot be frozen after 24-hour collection, the pH of the specimen must be adjusted to between 1-3 using 6N HCl.

Transport to the laboratory frozen.

• Boric Acid used as a preservative (Boric acid ≥1250 mg/dL may cause citrate results to be reduced by approximately 30%)
• Multivitamin ≥397.5 mg/dL (estimated as 1 pill per day) may cause citrate results to be unmeasurable. Results of interference testing may not be representative of in-vivo characteristics of multivitamin consumption.

 See patient report.

• Citric Acid (Citrate), 24-Hour Urine
• Citrate Excretion, Urine
• Citrate, Urine