This article deals with the features of zinc metabolism in the body, its biological role, the causes and signs of hypozincemia and hyperzincemia, as well as the use of zinc in therapeutic practice. The study of the characteristics of zinc absorption, its distribution in the body, features of its excretion is of huge importance for the correction of its daily dietary requirements and its metabolic shifts in various diseases. Zinc is an essential microelement with diverse biological functions. On average, the recommended daily allowance for zinc is 10-15 mg. The richest sources of zinc in diet include legumes, sesame, peanuts, bran, egg yolk, liver, and meat. Zinc absorption is inhibited by phytates, copper, phosphates, calcium, and dietary fibers. EDTA, pancreatic juice, citric acid, ascorbic acid, picolinic acid, glycine, glutamate, estrogens, progestins, testosterone, and some peptides increase zinc absorption. It is known that zinc performs various functions in the body. In particular, zinc is involved in cell growth, apoptosis and metabolism, as well as in the regulation of endocrine, immune and neural functions. At the cellular level, zinc stimulates polysome formation. Furthermore, it inhibits iron-mediated free radical oxidation. There is strong evidence that zinc plays an important role in nucleic acid metabolism, in the processes of transcription, as well as in the stabilization of nucleic acids. Zinc is known to accelerate collagen synthesis promoting wound healing. In addition, it has a stabilizing effect on the cytoplasmic membrane, preventing the release of hydrolytic enzymes. Zinc is considered to be of huge importance in the development of the skeleton. In mitochondria, zinc inhibits electron transport in the respiratory chain. This property is observed in spermatozoa, where there is a lot of zinc and low respiratory activity is found. Zinc is essential for the development of brain tissue. Moreover, zinc in the body is a component of more than 300 enzymes. Zinc is involved in the retinol reduction in the retina. It is reported that zinc stabilizes the structure of insulin due to its ability to bind insulin hexamers. Zinc is included in the structure of the active hormone of the thymus gland – thymulin. Furthermore, it participates in the formation of the tertiary structure of gonadotropins and other hormones. Zinc is a lipotropic factor for the liver, which is involved in the formation of unsaturated fatty acids along with vitamin E. In patients with acute zinc deficiency, irritability, depression, ageusia, and twilight vision disorders are observed. Excess amounts of zinc can cause acute and chronic poisoning. There are converging lines of evidence concerning the effectiveness of treatment with zinc salts in patients with type 2 herpes, Wilson's disease, chronic hepatitis B, children with duodenal ulcers and chronic gastroduodenitis. Clinical studies have confirmed the need for administration of zinc-containing drugs in the treatment of infectious intestinal diseases in children.
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