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Test Code ZNS Zinc, Serum

Reporting Name

Zinc, S

Useful For

Detecting zinc deficiency

Performing Laboratory

Mayo Medical Laboratories in Rochester

Specimen Type

Serum


Specimen Required


Collection Container/Tube: 6-mL Plain, royal blue-top Vacutainer plastic trace element blood collection tube (T184)

Submission Container/Tube: 7-mL Mayo metal-free, screw-capped, polypropylene vial (T173)

Specimen Volume: 0.8 mL

Collection Instructions:

1. Allow the specimen to clot for 30 minutes; then centrifuge the specimen to separate serum from the cellular fraction. Serum must be removed from cellular fraction within 4 hours of specimen collection. Avoid hemolysis.

2. Remove the stopper. Carefully pour specimen into a Mayo metal-free, polypropylene vial, avoiding transfer of the cellular components of blood. Do not insert a pipet into the serum to accomplish transfer, and do not ream the specimen with a wooden stick to assist with serum transfer.

3. See Trace Metals Analysis Specimen Collection and Transport in Special Instructions for complete instructions.

Additional Information:

1. High concentrations of gadolinium, iodine, and barium are known to interfere with most metals tests. If gadolinium-, iodine-, or barium-containing contrast media has been administered, a specimen should not be collected for 96 hours.

2. If ordering the trace element blood collection tube from BD, order catalog #368380.


Specimen Minimum Volume

0.2 mL

Specimen Stability Information

Specimen Type Temperature Time
Serum Refrigerated (preferred) 14 days
  Ambient  14 days
  Frozen  14 days

Reference Values

0-10 years: 0.60-1.20 mcg/mL

≥11 years: 0.66-1.10 mcg/mL

Day(s) and Time(s) Performed

Monday; 2 p.m.; Tuesday through Friday; 5 p.m.; Saturday; 2 p.m.

Test Classification

This test was developed and its performance characteristics determined by Mayo Clinic in a manner consistent with CLIA requirements. This test has not been cleared or approved by the U.S. Food and Drug Administration.

CPT Code Information

84630

LOINC Code Information

Test ID Test Order Name Order LOINC Value
ZNS Zinc, S 5763-8

 

Result ID Test Result Name Result LOINC Value
8620 Zinc, S 5763-8

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. The peptidases, kinases, and phosphorylases are most sensitive to zinc depletion. Zinc is a key element required for active wound healing.

 

Zinc depletion occurs either because it is not absorbed from the diet (excess copper or iron interfere with absorption) or it is lost after absorption. Dietary deficiency may be due to absence (parenteral nutrition) or because the zinc in the diet is bound to phytate (fiber) and not available for absorption. Excess copper and iron in the diet (eg, iron supplements) interfere with zinc uptake. Once absorbed, the most common route of loss is via exudates from open wounds or gastrointestinal loss. Zinc depletion occurs in burn patients who lose zinc in the exudates from their burn sites. Hepatic cirrhosis causes excess loss of zinc by enhancing renal excretion. Other diseases that cause low serum zinc are ulcerative colitis, Crohn's disease, regional enteritis, sprue, intestinal bypass, neoplastic disease, and increased catabolism induced by anabolic steroids. The conditions of anorexia and starvation also result in low zinc levels.

 

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

Normal serum zinc is 0.66 to 1.10 mcg/mL.

 

Burn patients with acrodermatitis may have zinc as low as 0.4 mcg/mL; these patients respond quickly to zinc supplementation.

 

Elevated serum zinc is of minimal clinical interest.

Clinical Reference

1. Tucker SB, Schroeter AL, Brown PW Jr, McCall JT: Acquired zinc deficiency: cutaneous manifestations typical of acrodermatitis enteropathica. JAMA 1976;235:2399-2402

2. Skelton JA, Havens PL, Werlin SL. Nutrient deficiencies in tube-fed children. Clin Pediatr 2006;45(1):37-41

3. Zorbas YG, Kakuris KK, Neofitov IA, Afoninos NI: Zinc utilization in zinc-supplemented and -unsupplemented healthy subjects during and after prolonged hypokinesis. Tr Elem Electro 2008;25:60-68

Analytic Time

1 day

Reject Due To

Hemolysis

Mild reject; Gross reject

Lipemia

Mild OK; Gross OK

Icterus

Mild OK; Gross reject

Other

NA

Method Name

Dynamic Reaction Cell-Inductively Coupled Plasma-Mass Spectrometry (DRC-ICP-MS)

Forms

If not ordering electronically, complete, print, and send a General Request Form (T239) with the specimen (http://www.mayomedicallaboratories.com/it-mmfiles/general-request-form.pdf).