Zinc, Urine

Diagnostic Use

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 fibre 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. 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 faeces. 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.

Department

Lipids/Trace Metals

Delphic Registration Code

UZN

Laboratory Handling

Separating

Aliquot for UCRN to Core Laboratory

Laboratory

To avoid contamination, the specimen must be mixed well and then a 10mL aliquot is poured into a galanti tube BEFORE the 24 volume is measured.

Test Adds

Ambient 14 days, refrigerated (preferred) 28 days, frozen 28 days

Turnaround Time

14 days

Test Code

4273