Clinical significance
Zinc is a trace metal in the body, where it is involved in many activities. It is present in many enzymes (metalloenzymes) and plays a role in protein synthesis, growth, sperm production and wound healing. It also regulates glucose balance and cell-mediated immunity. Zinc is normally present in the diet (meat, fish, eggs, milk), is absorbed in the gastrointestinal tract and is eliminated mainly in the stool. In industry it is used in galvanising, alloy production and electric batteries. Exposure to zinc salt fumes can cause irritation of the skin, respiratory tract and gastrointestinal tract.
Clinical indications
Occupational exposure to zinc. Deficiency states.
Sample type
The patient needs to give a blood or urine sample.
Preparation
You must fast for at least 8 hours; a small amount of water is allowed. A urine sample passed at the start or end of the work shift is required.
Notes
Corticosteroids, interferon, contraceptives and phenytoin can lower its blood concentration. Diuretics can increase its elimination in the urine.
Plasma zinc is almost entirely bound to albumin, so a fall in blood albumin lowers its concentration; decreases also occur in pregnancy, inflammation and stress.