Citric acid, 24-hour urine-13495
Test info
Citric acid, 24-hour urine
13495
LAB13495
CIT
Citrate excretion, urine
Citrate, urine
Citrate 24-hour urine
Citrate, urine
Citrate 24-hour urine
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
Urine, 24-hr
10 mL aliquot of a 24-hour urine collection
2.5 mL aliquot of a 24-hour urine collection
Collect 24-hour urine with 30 mL 6N HCl
CAUTION: Strong acid
How to collect a 24-hr urine sample
Keep container refrigerated during collection.
- Measure and record the 24-hour total volume
- Mix well
- Transfer a 10 mL aliquot to a Transfer vial/tube with cap - 12mL (LabCorp) the laboratory.
- Alternatively, the sample may be frozen without added acid.
- Measure and record the 24-hour total volume
- Mix well
- Transfer a 10 mL aliquot to a Screw-cap polypropylene frozen transport vial/tube - 4mL (LabCorp)
- Freeze within 24 hours of end of collection
- Total volume
Refrigerated (preferred) - 29 days, if acidified
Ambient - 29 days, if acidified
Frozen - 49 days, no acidification required
Freeze/thaw cycles - stable x 5
- Boric acid used as a preservative
Performance
LabCorp Burlington (016865): R-LC
Mo - Fr
2 - 7 days
Nuclear magnetic resonance (NMR) or Enzymatic
Clinical and Interpretive info
320 - 1240 mg/24 hours
A 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.
Billing
82507
Result 21203-5
Tracking
03/29/2019
12/29/2023
12/29/2023