Zinc, Plasma or Serum

Zinc, Plasma or Serum

Number
	001800
CPT
	84630
Related Information
	Zinc, Urine
Synonyms
	Zn, Serum
Specimen
	Plasma (preferred) or serum
Volume
	2 mL
Minimum Volume
	0.6 mL
Container
	Royal blue-top (EDTA or heparin) tube or red-top tube.
Collection
	Separate serum from cells within 45 minutes of collection and transfer to a plastic transport tube. Plasma may be separated immediately and transfer to a plastic transport tube for shipment to the laboratory.
Storage Instructions
	Maintain specimen at room temperature.
Causes for Rejection
	Gel-barrier tube; unspun red-top tube
Reference Interval
	Environmental exposure: 70-150 μg/dL
Use
	Monitor exposure to zinc; evaluate suspected nutritional inadequacy, especially in enteral or parental nutrition, critically ill or burn patients; cases of diabetes or delayed wound healing; growth retardation; follow therapy, for example when higher intravenous zinc doses are used to balance excessive ongoing GI losses in long-term total parenteral nutrition; follow oral zinc therapy in Wilson disease; confirm acrodermatitis enteropathica and follow therapy
Limitations
	Levels may be low in fever, sepsis, estrogen therapy, stress, or myocardial infarction, reflecting mobilization from serum to the liver by interleukin. Levels are usually low in uremia with normal tissue levels. Levels may be high in familial hyperzincemia without toxicity or high zinc stores.
Methodology
	Atomic absorption spectrometry (AAS); inductively-coupled plasma-mass spectrometry (ICP-MS)
Additional Information
	Chronic oral zinc supplementation interferes with copper absorption and may precipitate copper deficiency. Albumin is the primary zinc binding protein: zinc levels should be interpreted with awareness of serum albumin level.
References
	Alfrey AC, “Essential Trace Elements,” The Kidney: Physiology and Pathophysiology, 2nd ed, Seldin DW and Giebisch G, eds, New York, NY: Raven Press, Ltd, 1992, 2993-3003. Ruz M, Cavan KR, Bettger WJ, et al, “Development of a Dietary Model for the Study of Mild Zinc Deficiency in Humans and Evaluation of Some Biochemical and Functional Indices of Zinc Status,” Am J Clin Nutr, 1991, 53(5):1295-303.