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HelpTest Code MISC2MAYOZNU Zinc, 24 Hour, Urine
Reporting Name
Zinc, 24 Hr, UUseful For
Identifying the cause of abnormal serum zinc concentrations using a 24-hour urine specimen
Performing Laboratory
Mayo Clinic Laboratories in Rochester
Specimen Type
UrineOrdering Guidance
The use of blood testing is recommended for children younger than 10 years. Order ZN_S / Zinc, Serum.
Necessary Information
24-Hour volume (in milliliters) is required.
Specimen Required
Patient Preparation: High concentrations of barium are known to interfere with this test. If barium-containing contrast media has been administered, the specimen should not be collected for at least 96 hours.
Supplies: Urine Tubes, 10 mL (T068)
Collection Container/Tube: Clean, plastic urine collection container with no metal cap or glued insert
Submission Container/Tube: Plastic urine tube or clean, plastic aliquot container with no metal cap or glued insert
Specimen Volume: 10 mL
Collection Instructions:
1. Collect urine for 24 hours.
2. Refrigerate specimen within 4 hours of completion of 24-hour collection.
3. See Metals Analysis Specimen Collection and Transport for complete instructions.
Additional Information: See Urine Preservatives-Collection and Transportation for 24-Hour Urine Specimens for multiple collections.
Specimen Minimum Volume
0.4 mL
Specimen Stability Information
| Specimen Type | Temperature | Time | Special Container |
|---|---|---|---|
| Urine | Refrigerated (preferred) | 28 days | |
| Ambient | 28 days | ||
| Frozen | 28 days |
Special Instructions
Reference Values
0-17 years: Not established
≥18 years: 109-1,476 mcg/24 h
Day(s) Performed
Monday, Thursday
Test Classification
This test was developed and its performance characteristics determined by Mayo Clinic in a manner consistent with CLIA requirements. It has not been cleared or approved by the US Food and Drug Administration.CPT Code Information
84630
LOINC Code Information
| Test ID | Test Order Name | Order LOINC Value |
|---|---|---|
| ZNU | Zinc, 24 Hr, U | 5765-3 |
| Result ID | Test Result Name | Result LOINC Value |
|---|---|---|
| 8591 | Zinc, 24 Hr, U | 5765-3 |
| TM8 | Collection Duration | 13362-9 |
| VL5 | Urine Volume | 3167-4 |
Clinical Information
Zinc is an essential element; it is a critical cofactor for carbonic anhydrase, alkaline phosphatase, RNA and DNA polymerases, alcohol dehydrogenase, and many other physiologically important proteins. Zinc is a key element required for active wound healing.
Zinc depletion occurs because it is either not absorbed from the diet (excess copper or iron interfere with absorption) or lost after absorption. Dietary deficiency may be due to absence (parenteral nutrition), or because the zinc in the diet is bound to fiber and not available for absorption. Once absorbed, the most common route of loss is via exudates from open wounds, such as third-degree burns, or gastrointestinal loss as in colitis. Hepatic cirrhosis also causes excess loss of zinc by enhancing renal excretion. The peptidase, kinase, and phosphorylase enzymes are most sensitive to zinc depletion.
Zinc excess is not of major clinical concern. The popular American habit of taking megavitamins (containing huge doses of zinc) produces no direct toxicity problems. Much of this zinc passes through the gastrointestinal tract and is excreted in the feces. The excess fraction that is absorbed is excreted in the urine. The only known effect of excessive zinc ingestion relates to the fact that zinc interferes with copper absorption, which can lead to hypocupremia.
Interpretation
Fecal excretion of zinc is the dominant route of elimination. Renal excretion is a minor, secondary elimination pathway. Normal daily excretion of zinc in the urine is in the range of 20 to 967 mcg/24 h.
High urine zinc associated with low serum zinc may be caused by hepatic cirrhosis, neoplastic disease, or increased catabolism.
High urine zinc with normal or elevated serum zinc indicates a large dietary source, usually in the form of high-dose vitamins.
Low urine zinc with low serum zinc may be caused by dietary deficiency or loss through exudation common in burn patients and those with gastrointestinal losses.
Method Description
The metal of interest is analyzed by triple-quadrupole inductively-coupled plasma mass spectrometry.(Unpublished Mayo method)
Report Available
2 to 5 daysReject Due To
All specimens will be evaluated at Mayo Clinic Laboratories for test suitability.Method Name
Triple-Quadrupole Inductively-Coupled Plasma Mass Spectrometry (ICP-MS/MS)