Zinc (Zn)

Chemical Pathology

Notes

Trace element analysis including zinc is not routinely performed in the normal population. Zinc levels are requested whenever a deficiency is suspected due to the medical history or clinical signs and symptoms of the patient.

For patients receiving total parenteral nutrition (TPN), zinc levels should be requested at baseline (along with copper and CRP) and then every 2 - 4 weeks depending on results. Deficiency is common but patients are more at risk if anabolic.

Note that zinc levels decrease with acute phase reaction, whereas copper levels increase.

Sample requirements

For adults, 6 ml of blood taken into a trace element tube.

For children and neonates, a minimum of 1 ml taken into a Teklab trace element tube.

Storage/transport

Do not store. Send at ambient temperature to the laboratory the same day.

Required information

Relevant clinical details.

Turnaround times

The samples are sent to a referral laboratory for analysis with results expected back within 2 weeks. If results are required more quickly for clinical reasons, please contact the duty biochemist.

Reference ranges

Zinc: 11-19 µmol/L

• Plasma zinc levels are a relatively crude index of zinc status in a patient.
• Zinc exhibits diurnal variation in healthy individuals and is affected by a number of factors including acute phase reaction, certain drugs and pregnancy.
• Concomitant measurement of CRP may be useful in some circumstances as an aid to interpreting a low zinc concentration.

Further information

NICE Guidelines CG32 Nutrition support in adults 2006

To learn more about trace elements visit Lab Tests Online

Page last updated: 07/02/2019