Zinc (Zn)
Why this test?
To assess the balance of zinc in the body;
For diagnosis of zinc deficiency (including subclinical);
For the diagnosis of zinc intoxication.
In what cases is it prescribed?
When examining risk group patients for the development of zinc deficiency (children and adolescents, pregnant women and women, patients who have been on total parenteral nutrition for a long time, patients with chronic diseases);
with enteropathic acrodermatitis symptom complexes (characteristic periorificial rash, chronic diarrhea and partial or total alopecia);
when examining a patient with reference to occupational contact with zinc.
Test information
Zinc is a trace element necessary for normal cell growth and differentiation. It is a cofactor of more than 200 enzymes (transferases, hydrolases, isomerases), is part of some transcription factors (so-called zinc fingers) and stabilizes cell membranes. Basically, a person receives zinc with food, meat, dairy and seafood products, as well as cereals, nuts and vegetables are the richest in this trace element. Zinc absorption occurs in the duodenum and jejunum. Some food components (for example, proteins of animal origin) contribute to the absorption of zinc, and, conversely, phytic acid and iron prevent its active absorption. The daily need for zinc depends on the age and physiological state of the body: for an adult man, the recommended rate is 11 mg per day, for an adult woman - 8 mg. Pregnant women, nursing mothers, children and adolescents need up to 12-15 mg of zinc per day. Both deficiency and excess of zinc adversely affect the functioning of many systems and organs. To assess the balance of zinc in the body, diagnose its deficiency or intoxication, its concentration in the blood is studied. It is believed that the level of zinc in the blood most accurately reflects its reserves in the body.
Zinc deficiency is described in some rare congenital metabolic diseases (enteropathic acrodermatitis) and is manifested by characteristic skin changes, alopecia and diarrhea. Clinically expressed nutritional deficiency of zinc is quite rare. On the other hand, subclinical deficiency of this trace element can be diagnosed in every third person. Lack of zinc most often occurs during the period of active growth, the greatest need for it is observed at the age of 10-12 years in girls and 11-14 years in boys. Subclinical zinc deficiency during puberty can cause impaired growth of the axial skeleton and mineralization of bone tissue. In addition, zinc deficiency occurs in patients on total parenteral nutrition, as well as in patients with chronic diseases. Repeated studies of the concentration of zinc in the blood are carried out to evaluate the treatment of the deficiency of this trace element when prescribing zinc-containing drugs. However, it should be noted that a low level of zinc in the blood does not always mean a lack of this trace element in the body. The concentration of zinc in the blood decreases during acute infectious and inflammatory processes, injuries, intense physical exertion and stress. Normally, the level of this element decreases in the postprandial period (after a meal).
Zinc intoxication can be observed when drinking beverages from galvanized containers. The main symptoms of acute food poisoning with zinc are nausea, abdominal pain, diarrhea, fever and increased sweating. A chronic excess of zinc is sometimes accompanied by impaired absorption of copper. Workers engaged in production related to the production or use of zinc are prone to the risk of acute inhalation poisoning by its vapors, this syndrome is called metal fever and is caused by the acute toxic effect of vapors of metal oxides on the upper and lower respiratory tract. Acute poisoning is accompanied by fever, cough, sore throat, nasal congestion, shortness of breath, weakness, and muscle pain. When examining the blood of such patients, it is sometimes possible to detect an increase in the concentration of zinc. It should be noted that the symptoms of metal fever are not specific for acute poisoning with zinc oxide vapors and are also observed when inhaling vapors of aluminum, manganese, copper, iron, lead, and other metals. Thus, the study of the level of zinc (as well as other metals) in the blood can be used in the diagnosis of occupational diseases. At the same time, an increase in the concentration of zinc in the blood is not always a sign of poisoning, for example, it is observed during prolonged fasting.
It is necessary to interpret the result of the analysis taking into account additional clinical, laboratory and instrumental studies.
