9297. Zinc

Zinc is an important trace element necessary for immunity, wound healing, cell growth, and metabolism. Serum zinc analysis determines its level in the blood. The test is necessary for the diagnosis of deficiency (in cases of poor nutrition, intestinal diseases, chronic diseases) or excess (rarely, due to occupational exposure or excessive intake of supplements). Deviations in zinc levels may indicate various conditions and help the physician with diagnosis and treatment.

Zinc is a vital element, one of the most abundant trace elements in the body, quantitatively second only to iron. Zinc is part of more than 300 metalloenzymes, including carbonic anhydrase, alkaline phosphatase, RNA and DNA polymerases, thymidine kinases, carboxypeptidases, and alcohol dehydrogenase. The key role of zinc in protein and nucleic acid synthesis explains the impairment of growth and wound healing observed with a deficiency of this element. It is involved in mechanisms related to the regulation of gene expression.

In food, zinc is predominantly bound to proteins, and its bioavailability depends on the digestion of these proteins. Zinc is most readily available in red meat and fish. Wheat germ and bran are also good sources of zinc.

Symptoms of zinc deficiency are often associated with a diet low in animal protein and rich in cereals, which contain phytates that bind zinc. Zinc absorption may be reduced by iron and copper preparations. A decrease in zinc levels is observed in patients with burns (exudation from burn surfaces) and in patients with liver cirrhosis due to increased renal excretion. Ulcerative colitis, Crohn's disease, enteritis, sprue, neoplasms, increased catabolism caused by anabolic steroids, anorexia, and fasting lead to a decrease in zinc levels. Rare cases of excessive zinc intake are associated with the use of galvanized containers for drinking liquids and the intake of zinc as part of multivitamins, which can interfere with copper absorption and lead to a decrease in its serum level. Excess zinc may cause gastrointestinal irritation.

Absorbed zinc is actively incorporated into metalloenzymes and plasma proteins in the liver. Blood plasma contains less than 1% of the body's total zinc. Most plasma zinc is bound to albumin (80%), while the remainder is mainly bound to alpha-2-macroglobulin. In erythrocytes, almost all zinc is part of carbonic anhydrase. The zinc content in erythrocytes is approximately 10 times higher than in plasma. Zinc is eliminated from the body through excretion in bile and urine.

Clinical manifestations of zinc deficiency are nonspecific, vary, and depend on the degree and duration of the deficiency. Symptoms of deficiency include growth retardation, increased frequency of infections, diarrhea, loss of appetite, changes in cognitive functions, impaired carbohydrate metabolism, anemia, enlargement of the liver and spleen, skin lesions, hair loss, and impaired vision.

• For individuals with signs of zinc deficiency: growth retardation in children, frequent infections, poor wound healing, loss of taste and smell, skin rashes (especially around the mouth and on the hands), diarrhea, and hair loss.
• For patients with diseases that may lead to zinc deficiency: Crohn's disease and ulcerative colitis, malabsorption syndrome, chronic liver and kidney diseases, diabetes mellitus, HIV infection.
• For individuals following strict vegetarian or vegan diets without proper dietary balancing.
• For patients taking certain medications that may affect zinc levels (for example, diuretics, ACE inhibitors).
• For individuals with suspected zinc excess (rarely): nausea, vomiting, abdominal pain, diarrhea (usually associated with excessive intake of zinc supplements or occupational exposure).
• For children with delayed puberty.
• For pregnant women, especially those with signs of zinc deficiency.
• For newborns, especially premature infants or those with low birth weight.

• Venous blood

In order to exclude factors that may affect the test results, we recommend to follow the preparation rules: