What is it
Zinc is a chemical element (or more precisely a metal) rather abundant on the earth’s crust, naturally present in air and water, and used since ancient times in the production of common metal alloys (such as brass).
Identified on the periodic table of elements by the symbol Zn and the atomic number 30, this element knows a large number of applications in modern industry.
The technology sector, for example, extracts several tons per year (along with metals such as iron, aluminum and copper) for the production of smartphones and computers; the steel industry, on the other hand, uses it in galvanizing (or galvanization) of iron and steel objects; while the production sector of paints and varnishes obtains from one of its compounds (zinc oxide) the white color.
Zinc, however, is also an indispensable substance for our body, as it is a constituent element of over two hundred enzymes and many other proteins.
In particular, it is essential for the functioning of enzymes that regulate cellular respiration (the so-called cellular metabolism), those that have an antioxidant action and some proteins that allow you to unravel DNA (the genetic material that cells keep tightly tangled in chromosomes) and then read the instructions.
Just like the other substances included in the group of trace elements (iron, copper, fluorine, iodine, selenium, chromium and cobalt), this mineral is present in our body in small traces.
According to statistics, the overall content of zinc in the human body varies between 1.4 and 3 grams.
Zinc accumulates predominantly within the cells of muscles, bones, skin, liver and hair, but is also present in brain tissues, sperm and, in small amounts, plasma and white blood cells.
These reserves are not easily used, so the diet must contain sufficient amounts to meet the body’s daily needs.
Food sources
Zinc is one of the substances that make up the tissues of plant and animal organisms. Among the foods richest in zinc, in fact, there are oysters, cereals, beef, sheep, pork, mushrooms, cocoa, nuts and egg yolk.
However, cereals contain substances (fiber and phytates) that reduce their absorption. Fermentation processes, such as leavening bread, lead to the degradation of phytates, thus reducing the risk of deficiency.
The absorption of zinc, which takes place in the small intestine, is facilitated by ligands present in red meat while it is hindered not only by phytates, but also by some milk proteins, such as casein, and by high calcium intakes.
Effects
In addition to contributing to growth, zinc fights the negative effects of free radicals and the cellular aging processes related to them, stimulates the functioning of the immune system, facilitates the healing of wounds and ulcers and hinders the formation of acne. It can help in the prevention of infertility treatment.
Deficiency
Zinc deficiency can be due to insufficient or poor absorption, often associated with a diet rich in cereals but low in protein, alcoholism and advanced age, or excessive urinary elimination.
It can be found, for example, in the elderly with problems affecting the circulatory system, who often, in an attempt to maintain normal cholesterol values, reduce the consumption of meat, and therefore also that of zinc.
Sometimes the deficiency depends on diseases such as chronic diabetes, gastrointestinal disorders and liver cirrhosis, and is manifested by an increase in prolonged infections. But even some drugs can cause a zinc deficiency; These include diuretics, corticosteroids and MAOI antidepressants.
The symptoms related to zinc deficiencies are very varied:
- skin changes,
- fatigue
- loss of appetite,
- slow wound healing,
- decreased immune response with susceptibility to infections,
- alopecia,
- decreased taste sensitivity (with possible loss of taste)
- and night blindness.
A strong zinc deficiency can cause hypogonadism, i.e. an inadequate functioning of the ovaries and testes and, if it occurs during the fetal or growth period, can cause dwarfism or slowing development.
Diagnosis
The doctor makes a diagnosis of zinc deficiency, evaluating the symptoms described by the person and his response to zinc supplements. If necessary, he may order blood and urine tests, but these may prove ineffective in detecting the level of zinc present in the body.
Recommended doses
According to SINU (Italian Society of Human Nutrition), the recommended intake level
(LARN) for zinc corresponds to:
| Infants | 6-12 months | 3 mg |
| Children-adolescents | 1-3 years | 5 mg |
| 4-6 years | 6 mg | |
| 7-10 years | 8 mg | |
| Males | 11-17 years | 12 mg |
| Females | 11-17 years | 9 mg |
| Adults | ||
| Males | > 18 years | 12 mg |
| Females | > 18 years | 9 mg |
| Pregnancy | 11 mg | |
| Nursing | 12 mg |
Integration
In all cases of reduced intake or increased need it is advisable to resort to supplements.
Precautions
If you take high doses of supplements with zinc, it is also good to take a vitamin A supplement, whose absorption can be hindered by this element.
Normally, the mechanisms regulating the absorption of zinc allow to avoid the risk of an excessive intake of zinc, an element which, moreover, has little toxicity.
Cases of excessive intake, which causes fever, nausea, vomiting and diarrhea, are mostly related to contamination of food and drink by galvanized containers used for storage. These containers can in fact release zinc when left open, especially if their content is strongly acidic.
More rarely, the intake of too high quantities of zinc may be due to exposure to the fumes generated by the combustion of this substance, which, as we have seen, is used in various industrial production activities.
In these cases, the symptoms may be those of rapid breathing, excessive sweating, fever or metallic taste in the mouth.
Joycelyn Elders is the author and creator of EmpowerEssence, a health and wellness blog. Elders is a respected public health advocate and pediatrician dedicated to promoting general health and well-being.
The blog covers a wide range of topics related to health and wellness, with articles organized into several categories.