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
  

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.

  
  1. Measure and record the 24-hour total volume
  2. Mix well
  3. Transfer a 10 mL aliquot to a Transfer vial/tube with cap - 12mL (LabCorp) the laboratory.
    1. Alternatively, the sample may be frozen without added acid.
  
  1. Measure and record the 24-hour total volume
  2. Mix well
  3. Transfer a 10 mL aliquot to a Screw-cap polypropylene frozen transport vial/tube - 4mL (LabCorp)
  4. 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