Zinc is an essential microelement, a structural component of enzymes, proteins, cell receptors, biological membranes, necessary for the complete breakdown of proteins, fats and carbohydrates, the formation of the genetic material of cells, nucleic acid metabolism. Mention of the mineral is first found in the writings of the Swiss alchemist K. M. Paracelsus under the words "zinken", "zincum", meaning "scar". This is due to the fact that zinc metal crystals visually resemble needles. Currently, the trace element is designated under the symbol "Zn" and has 66 minerals. The most common of them are sphalerite, zincite, franklinite. Zinc is present in almost all cells of the body, but it is most concentrated in bone, nervous and muscle tissues (60%).
Influence on the human body
Zinc regulates the activity of more than 200 enzyme structures, and also takes part in the formation of the most important hormones, neurotransmitters, blood cells, creating favorable conditions for body cells to full functioning.
Biological significance of zinc: improves cognitive functions (attention, memory, mood); normalizes the work of the cerebellum and brain; increases the synthesis and hypoglycemic effect of insulin; increases the protective properties of neutrophils and macrophages, improving the immune status of the body; stabilizes blood sugar levels; regulates fatty acid oxidation reactions; improves visual acuity, taste perception, smell (together with vitamin A ); potentiates the synthesis of digestive enzymes; participates in the processes of hematopoiesis, respiration, decoding of information stored in genes; stimulates the regeneration of new tissues; regulates the activity of enzyme systems; activates bone formation and tissue regeneration; participates in the synthesis of sex hormones, increases the activity of spermatozoa; accelerates the production of its own antibodies and antioxidants; maintains the concentration of tocopherol in the blood, facilitating its absorption; increases libido, increases potency; improves the functional state of the skin, reducing acne, dryness; participates in the mechanisms of formation and decay of nucleic acids, protein and carbohydrate structures; accelerates the removal of toxic substances from the body, including excess carbon dioxide; participates in the mechanisms of muscle contraction; normalizes the transport "ability" of hemoglobin; potentiates a decrease in nonspecific permeabilitycell membranes.
In addition, zinc reduces the toxic effect of heavy metals on the body by 30%.
Zinc reserves in the body of adults weighing 70 kilograms are 1.5-3 grams, depending on the age and sex of the person, the presence of concomitant diseases, the condition of the intestinal mucosa.
Moreover, 98% of the substance is concentrated inside the cellular structures, and 2% in the blood serum. The daily requirement for zinc is:
- for girls up to six months - 2 milligrams;
- for boys under 6 months, 3 milligrams;
- for children under 3 years old - 3-4 milligrams;
- for preschoolers 4 to 8 years old, 5 milligrams;
- for adolescents 9 to 13 years old, 8 milligrams;
- for girls from 14 to 18 years old - 9 milligrams;
- for boys from 14 to 18 years old - 11 milligrams;
- for women aged 19 to 50, 12 milligrams;
- for men aged 19 to 50, 15 milligrams;
- for mature males from 50 to 80 years old - 13 milligrams;
- for postmenopausal women aged 50 to 70, 10 milligrams;
- for pregnant women, 14-15 milligrams;
- for nursing mothers - 17-20 milligrams.
The tolerable upper intake level for zinc without health effects is 25 milligrams. The need for a microelement increases with a deficiency of protein in the daily menu, profuse sweating, intense sports, use of oral contraceptives, mental overload, and taking diuretics.
Deficiency and excess
Zinc deficiency, in contrast to overdose, is a common phenomenon, which is especially common in people living in regions with depleted soil or an excess of copper ions in water (America, Australia, Russia, Ukraine).Other causes of zinc deficiency:
- poor dietary intake;
- chronic diseases of the kidneys, liver, intestines;
- nutrient malabsorption, including in vegetarianism;
- sickle cell anemia;
- malignant tumors;
- decreased thyroid function;
- pancreatic lesion;
- long-term use of corticosteroids, estrogens, diuretics;
- helminthic infestations;
- mechanical injuries, especially extensive burns;
- excessive concentration of salts of heavy metals (cadmium, mercury, lead, copper) in the body;
- consequences of surgery (short bowel syndrome, artificial communication of the ileum and jejunum);
- alcohol abuse, caffeine.
Symptoms of zinc deficiency are extremely variable, due to damage to various organs, tissues and body systems. Signs of micronutrient deficiency:
- deterioration in the functional state of hair and nails (alopecia, reduced pigmentation of individual strands, slower hair growth, delamination of horny plates);
- weight loss;
- skin diseases (dermatitis, eczema, psoriasis, furunculosis, scaly rashes on the body, acne, dry skin, slow wound healing, trophic ulcers);
- neurological disorders (changes in gait and speech, hyperactivity, tremors, decreased attention, dementia, sleep disturbance, depression, fatigue);
- eye damage (cataract, conjunctival inflammation, corneal edema);
- loss of smell, taste disturbances, mouth ulcers;
- decreased immunity (frequent respiratory illnesses, allergic reactions);
- growth retardation, delayed puberty in children;
- dyspeptic disorders;
- decrease in the concentration of insulin in the blood.
A long-term lack of zinc in the body is fraught with a decrease in the function of the pituitary gland and sex glands, impaired carbohydrate metabolism, an increased risk of neoplasms, and the occurrence of prostate adenoma. In addition, insufficiency of the mineral in pregnant women, in half of the cases, causes atonic bleeding, the birth of weakened children, the onset of premature or prolonged labor. To eliminate a mild form of trace element deficiency, the daily menu is enriched with natural sources (see paragraph "Food sources of zinc"). A severe form of the disorder is eliminated with the help of pharmacological agents containing a mineral ("Zincteral", "ZincoVital", "Zinkita"). However, it is important not to overdo it with dietary supplements, since zinc intake above 150-200 milligrams per day causes an overdose, which is accompanied by gastrointestinal disorders, nausea, vomiting, and headaches.
Given that zinc supports endocrine, immune and nervous system health, it is important to ensure a daily intake of the micronutrient in the body.
|Product name||Zinc content per 100 grams of product, milligrams|
|Wheat bran||15 -16|
|Veal liver (fried)||15|
|Beef, lamb, pork||7 - 9|
|Sesame, poppy seed||7.5 - 8|
|Pumpkin seeds (unroasted)||7.5|
|Chicken hearts (boiled)||7|
|Pine nuts||4 – 6.5|
|Lamb liver (fried)||6|
|Sunflower seeds, flax (unroasted)||5.5|
|Soy flour (coarse)||4.8|
|Beef tongue (boiled)||4.7|
|Wheat flour (whole grain)||3|
|Buckwheat, barley, oatmeal||2.5 – 3|
|Almond, cashew, hazelnut||2.1|
|Beans, peas||1.6 – 2.5|
|Dried apricots (untreated)||0.75|
|Prunes (without work)||0.45|
|Cauliflower, avocado, radish, carrot||0.3|
In addition, zinc in small quantities (up to 1 milligram per 100 grams of product) is found in almost all fruits, vegetables and berries. Remember, cooking plant foods, including grinding cereals, leads to a loss of 50 to 80% of the mineral.
Interactions with other nutrients
Absorption of organic zinc occurs throughout the intestinal tract, but most is absorbed in the jejunum. Interestingly, the mineral from animal foodorigin is better absorbed than from a vegetable source. This phenomenon is explained by the presence of phytic acid in the second product, which forms insoluble salts with zinc ions. In addition, the degree of assimilation of the element is influenced by some compounds that enter the body together with food. Consider the compatibility of zinc and other substances.
- Organic vitamin A (beta-carotene, carotenoids) increases zinc bioavailability.
- Calcium, lithium and phosphorus ions (in small amounts) enhance the pharmacological properties of the mineral.
- Zinc and copper"compete" for intestinal absorption, so "Cu" can cause "Zn" deficiency.
- Cadmium, lead reduce the concentration of the compound in the body, especially when there is a lack of protein in the diet.
- Simultaneous intake of zinc and calcium, copper, iron, manganese leads to a slowdown in the absorption of the first substance.
- Micronutrient deficiency exacerbates symptoms of vitamin E deficiency in the body.
- Tin slows down the absorption of zinc.
- Tetracycline preparations increase the excretion of the trace element.
- Folic acid supplementation in the presence of zinc deficiency impairs absorption of the mineral from food.
- Aspirin “washes out” the trace element from the body.
- With the combined use of zinc and iron, the absorption of the latter substance is reduced.
- The amino acids cysteine and histidine found in meat, eggs and seafood improve absorption of the mineral.
Natural fermentation or fermentation processes are used to enhance the absorption of zinc from foods, especially soybeans.
To maintain the health of the immune, reproductive, endocrine and nervous systems, foods containing zinc should be included in the daily menu.
Their highest concentration is observed in oysters, cereals, nuts, beans, berries, fruits. Given that zinc is part of hormones, enzymes, nerve endings, insufficient intake of the element in the body threatens menstrual irregularities, prostate enlargement, severe menopause, a decrease in the body's immune forces, and toxicosis during pregnancy. Remember, “zinc” products must be included in the diet of expectant mothers without fail, since they ensure the proper development and formation of the fetus.
- Khaliullina S. V. – Clinical significance of zinc deficiency in the body of a child (literature review) / Khaliullina S. V. // Vestn. modern clinical medicine. - 2013. - No. 3.
- Zimmermann M. - Trace elements in medicine (according to Burgerstein). - per. with him. M.: Arnebia. 2006. - 288 p.