Why does the body need selenium, what are the benefits and harms of the substance? The structure of the selenium atom.

Selenium was discovered in 1817 by Jens Jakob Berzelius. Berzelius's own story about how this discovery happened has been preserved: “I investigated, in collaboration with Gottlieb Hahn, the method used for the production of sulfuric acid in Gripsholm. We discovered a precipitate in sulfuric acid, partly red, partly light brown. ... Curiosity , prompted by the hope of discovering a new rare metal in this brown sediment, led me to investigate the sediment... I found that the mass (that is, the sediment) contained a hitherto unknown metal, very similar in its properties to tellurium. In accordance with this analogy I named the new body selenium (Selenium) from the Greek selhnh(moon), since tellurium is named after Tellus - our planet."

Being in nature, receiving:

The selenium content in the earth's crust is about 500 mg/t. Selenium forms 37 minerals, among which the first to be noted are ashavalite FeSe, clausthalite PbSe, timannite HgSe, guanajuatite Bi 2 (Se,S) 3, hastite CoSe 2, platinite PbBi 2 (S,Se) 3. Native selenium is occasionally found. Sulfide deposits are of major industrial importance for selenium. The selenium content in sulfides ranges from 7 to 110 g/t. The concentration of selenium in sea water is 4*10 -4 mg/l.
Selenium is obtained from waste from sulfuric acid and pulp and paper production, and also significant amounts are obtained from sludge from copper electrolyte production, in which selenium is present in the form of silver selenide. Several methods are used to obtain selenium from sludge: oxidative roasting with sublimation of SeO 2 ; oxidative sintering with soda, conversion of the resulting mixture of selenium compounds to Se(IV) compounds and their reduction to elemental selenium by the action of SO 2.

Physical properties:

The diversity of the molecular structure determines the existence of selenium in different allotropic modifications: amorphous (powdery, colloidal, glassy) and crystalline (monoclinic, a- And b-shapes and hexagonal g-form). Amorphous (red) powdered and colloidal selenium is obtained by reduction from a solution of selenous acid by rapid cooling of selenium vapor. Glassy (black) selenium is obtained by heating any modification of selenium above 220°C, followed by rapid cooling. It has a glassy luster and is fragile. Thermodynamically, hexagonal (gray) selenium is the most stable. It is obtained from other forms of selenium by heating until melting, slowly cooling to 180-210°C and holding at this temperature. Its lattice is built from parallel spiral chains of atoms.

Chemical properties:

At ordinary temperatures, selenium is resistant to oxygen, water and dilute acids. When heated, selenium reacts with all metals, forming selenides. In oxygen, with additional heating, it slowly burns with a blue flame, turning into dioxide SeO 2.
It reacts with halogens, with the exception of iodine, at room temperature to form the compounds SeF 6, SeF 4, SeCl 4, Se 2 Cl 2, SeBr 4, etc. With chlorine or bromine water, selenium reacts according to the equation:
Se + 3Br 2 + 4H 2 O = H 2 SeO 4 + 6 HBr
Hydrogen reacts with selenium at t >200°C, giving H 2 Se.
In conc. H 2 SO 4 in the cold, selenium dissolves, giving a green solution containing polymer cations Se 8 2+.
With water when heated and finally. In alkali solutions, selenium disproportionates:
3Se + 3H 2 O = 2H 2 Se + H 2 SeO 3 and 3Se + 6KOH = K 2 SeO 3 + 2K 2 Se + 3H 2 O
forming selenium(-2) and selenium(+4) compounds.
Similarly to sulfur, selenium dissolves when heated in solutions of Na 2 SO 3 or KCN, forming, respectively, Na 2 SSeO 3 (an analogue of thiosulfate) or KCNSe (an analogue of thiosulfate).

The most important connections:

The most typical oxidation states for selenium are -2, +4, +6.
Selenium(IV) oxide SeO 2- white shiny crystals with a polymer molecule (SeOsub>2)sub>n, m.p. 350°C. The vapors are yellowish-green in color and have the smell of rotten radish. Easily dissolves in water to form H 2 SeO 3 .
Selenous acid, H 2 SeO 3- white rhombic crystals. Highly hygroscopic. Highly soluble in water. Unstable, when heated above 70°C it decomposes into water and selenium(IV) oxide. Salts are selenites.
Sodium selenite, Na 2 SeO 3– colorless crystals, m.p. 711°C. Hygroscopic, highly soluble in water. When heated in an inert atmosphere, it decomposes into oxides. When heated in air, it oxidizes to selenate: 2Na 2 SeO 3 + O 2 = 2Na 2 SeO 4
Selenium(VI) oxide SeO 3- - colorless crystals, m.p. 121°C. It is hygroscopic, reacts with water with large heat release and the formation of H 2 SeO 4. Strong oxidizing agent, reacts violently with organic substances
Selenic acid, H 2 SeO 4- a colorless crystalline substance, highly soluble in water. It is toxic, hygroscopic, and a strong oxidizing agent. Selenic acid is one of the few compounds that, when heated, dissolves gold, forming a red-yellow solution of gold(III) selenate.
2Au + 6H 2 SeO 4 = Au 2 (SeO 4) 3 + 3H 2 SeO 3 + 3H 2 O
Selenates- salts of selenic acid. Sodium selenate Na 2 SeO 4 - crystals of orthorhombic system; tmelt 730 °C. Obtained by neutralizing the acid with sodium oxide, hydroxide or carbonate or by oxidizing sodium selenite. Slightly soluble in water, below 32 °C it crystallizes from aqueous solutions in the form of decahydrate Na 2 SeO 4 10H 2 O
Hydrogen selenide, H 2 Se- a colorless flammable gas with an unpleasant odor. The most toxic selenium compound. In air it is easily oxidized at ordinary temperatures to free selenium. It is also oxidized to free selenium by chlorine, bromine and iodine. When burned in air or oxygen, selenium(IV) oxide and water are formed. Stronger acid than H2S.
Selenides- compounds of selenium with metals. Crystalline substances, often with a metallic luster. There are monoselenides of the composition M 2 Se, MSe; polyselenides M 2 Se n (except Li), where n = 2-6; hydroselenides MHSe. Air oxygen is oxidized to selenium: 2Na 2 Se n + O 2 + 2H 2 O = 2n Se + 4NaOH

Application:

Selenium is used in rectifying semiconductor diodes, as well as for photovoltaic devices, electrophotographic copying devices, as phosphors in television, optical and signal devices, thermistors, etc. Selenium is widely used for decolorizing green glass and producing ruby ​​glasses; in metallurgy - to give steel a fine-grained structure and improve their mechanical properties; in the chemical industry - as a catalyst.
The stable isotope selenium-74 made it possible to create a plasma laser with colossal amplification in the ultraviolet region (about a billion times).
The radioactive isotope selenium-75 is used as a powerful source of gamma radiation for flaw detection.

Biological role and toxicity:

Selenium is present in the active centers of some proteins in the form of the amino acid selenocysteine. It has antioxidant properties, increases the perception of light by the retina, and affects many enzymatic reactions. The requirement of humans and animals for selenium does not exceed 50-100 mcg/kg of diet.

Polkovnikov A.A.
HF Tyumen State University, 581 group. 2011

Sources: Wikipedia: http://ru.wikipedia.org/wiki/Selenium
Chemist's Handbook website:

You've probably often read about microelements that are useful and necessary for the body. One of these substances is the chemical element Se (selenium). It was discovered as an independent element only two centuries ago, and its necessity for the body was proven much later.

Selenium Facts

Here are some interesting facts from the difficult and unusual history of getting to know selenium and its role in the human body:

• It was discovered as an independent element in 1817 by J. Ya. Berzelius.
• Industrial use begins in the mid-19th century.
• The first solar cells were made using selenium.
• From 1900 to 1950, the use of selenium was extremely limited due to its proven toxicity.
• 1954 marked the publication of the first scientific article on the positive biological properties of selenium.
• Since the 1950s, the effects of selenium on the human and animal body have been studied.
• The selenium content in the body is 10-15 milligrams.
• The daily human need is 70-100 micrograms.
• Selenium is part of a whole group of enzymes.
• Both deficiency and excess of selenium negatively affect the body.

Despite being contained in the body in very small quantities, selenium is important for all human cells, tissues and organs, as it performs many important functions. This is due to its inclusion in a number of enzymes, as well as its presence in the nucleus of each cell. In order to understand what happens with an excess or deficiency of selenium, it is necessary to first describe its physiological effects.

The physiological functions of selenium include:

• Protecting the body from biological threats. As part of special proteins united in the group of selenoproteins, this element plays an important role in regulating the body's immune system. With its help, the body provides an adequate response to the introduction of bacteria, fungi, viruses, as well as protozoan microorganisms.
• Protecting the body from chemical threats. Both during functioning and from the external environment, the body constantly contains aggressive compounds that damage and destroy cells. Their action is resisted by a special, nonspecific antioxidant-antiradical defense system, which includes a number of enzymes, biologically active substances and some other factors, including cellular ones. Selenium is a component of a significant number of compounds from this system.
• Participation in the metabolism of fats, proteins and carbohydrates. Selenium is necessary for the regulation of normal synthesis of thyroid hormones, and also promotes the complete absorption of elements such as iodine from food and water. Indirectly, through these and other biologically active compounds, selenium affects all types of metabolism in the body.
• Regulation of cell division. Selenium, like some other elements, is a necessary factor for normal cell division. The presence of selenium in cells prevents mutations and the development of tumor cells, and in existing cancer cells, it triggers mechanisms for their destruction.
• Anti-inflammatory effect. It consists in the regulation of chemical reactions and the actions of biologically active molecules that are responsible for the course of the inflammatory - protective reaction. These substances are called inflammatory mediators, and selenium helps normalize their release. The role of this substance is especially important in alleviating conditions characterized by an excessive response of the body, such as bronchial asthma, arthritis, psoriasis and chronic forms of colitis.
• Detoxifying properties. Selenium has the ability to reliably bind and promote rapid removal from the body of heavy metal ions: cadmium, mercury, lead, synthetic drugs, a number of toxic compounds of biological nature - toxins of bacteria, fungi, protozoa.
• Cytoprotective effect. Thanks to selenium, the processes of aging and damage to both individual cells and the entire body are significantly inhibited. That is why the presence of this element in the required quantities contributes to the longest possible functioning of the cells of the central nervous system, heart muscle, liver and bone marrow.
• Reproductive effect. Selenium is metabolically very closely related to substances such as ascorbic acid (Vitamin “C”) and tocopherol (Vitamin E), biotin (Vitamin H). All these substances, and first of all, selenium, are extremely necessary for the normal functioning of the human reproductive system. The effect of selenium extends both to the synthesis of sex hormones and to the process of formation of germ cells.
• Other effects. Selenium plays an important role in the metabolism of other chemical elements in the body. This applies to iron, copper, iodine, zinc and others, and this influence is mutual and interconnected.

Important:Selenium is necessary for the body, as it participates in almost all processes in the human body. By itself, it is quite toxic, so what is important is the necessary intake of it into the body - within the range of 70 - 100 mcg per day. A deficiency of selenium in the body, just like its excess, leads to pronounced negative changes.

Factors leading to excess or deficiency of selenium

The main factors contributing to selenium deficiency in the body include:

• living in regions with low selenium content in the soil;
• diseases of the gastrointestinal tract with impaired absorption;
• practiced vegetarianism, fasting, excessive dieting;
• and alcohol consumption;
• taking certain pharmacological drugs - oral contraceptives, laxatives, statins, adsorbents.
• elderly age;
• excessive consumption of selenium during pregnancy, chronic intoxication, for example, with pollutants, in unfavorable environmental conditions;

A rarer condition is excess selenium intake into the body and is mainly associated with:

• dietary habits with an excess of foods rich in selenium - mainly seafood;
• unreasonable or excessive intake of selenium medications;
• accidental rapid intake of significant doses of selenium into the body;
• chronic excess intake of selenium into the body, for example, with a low level of safety precautions in some chemical industries.

With an abnormally low intake of selenium from water and food into the body over a long period of time, a number of negative phenomena are observed that can occur independently, disguise themselves as other diseases, or aggravate the picture of existing ones. For the convenience of describing such conditions, we will present them in the same sequence in which the physiological effects of this element were described.

As a result of selenium deficiency,:

• . Its protective properties are significantly weakened. Moreover, all components of the immune system are negatively affected - from leukocytes to antibodies. With prolonged and severe selenium deficiency, states of almost complete immune deficiency can occur. This is manifested by the body's susceptibility to infections of any type. Any infectious diseases are severe, with frequent complications, and are difficult to correct with medication. Recovery from selenium deficiency takes a long time and is rarely complete.
• Antioxidant protection. Selenium deficiency leads to rapid and massive damage to individual cells and rapid wear and tear of tissues and organs. The patient experiences various types of tissue dystrophies, atherosclerotic and other vascular changes. Rapid degeneration of tissues of the central nervous system, bone marrow, muscle fibers. The result of selenium deficiency is various nonspecific diseases, and also, most importantly, aggravation of the course of existing diseases, such as coronary heart disease, bronchial asthma, endocrine pathology and many, many others. This is manifested in more frequent exacerbations, maximum severity of clinical manifestations, more difficult recovery and short duration of remissions.
• Metabolism. Disturbances manifest themselves in aggravation of the course of existing endocrine disorders, as well as excess or, on the contrary, underweight, which cannot be actively corrected with the help of diets. There are often disturbances in water and salt metabolism, the metabolism of other important macro- and microelements, which cascade to even more profound negative changes in the body.
• Normal cell division. This condition is one of the risk factors for the development of tumors, both malignant and benign. If a situation arises where selenium deficiency occurs with tumors already existing in the body, this leads to a sharp increase in the growth and progression of tumors, the occurrence of relapses and the appearance of multiple metastases in malignant tumors.
• Anti-inflammatory function. Inflammatory reactions and processes associated with inflammatory mediators, such as bronchial asthma, allergic reactions of various types, are more pronounced and severe. In this case, they are much less amenable to drug correction.
• Cell protection. The protection of cells from biological toxins, organic and inorganic compounds, especially heavy metal ions, as well as toxic metabolic products of the body itself is sharply reduced, which manifests itself both in a decrease in the overall resistance of the body and in the appearance of a variety of diseases.
• Reproductive function. It is one of the first to suffer, especially among men. This not only in most cases is the cause of male infertility, but also leads to a decrease in the severity of desire and sexual activity. If selenium deficiency develops in women during pregnancy and this deficiency remains uncorrected, this can lead to various pathologies of fetal development. In some cases, a catastrophic lack of selenium causes spontaneous abortions and miscarriage.

Note!Selenium is quite a toxic substance!

Acute selenium intoxication is extremely rare and is observed when large doses of inorganic selenium are simultaneously ingested into the body, which is usually associated with accidental drug overdoses and man-made causes - accidents at selenium mining or processing facilities. In this case, clinical manifestations directly correlate with the amount of dose entering the body.

Symptoms usually include general toxic effects. The patient has:

• abdominal pain and frequent stools; This symptom gradually fades away over several days;
• constant nausea, vomiting, which does not bring relief, but is not profuse;
• a rather sharp, pronounced garlic odor from the mouth;
• severe headache, especially when moving, muscle pain;
• Occasionally, photophobia and lacrimation may occur in bright indoor lighting;
• weakness, increased fatigue, drowsiness without proper sleep.

Carrying out general detoxification measures in intensive care units is quite enough to help the body recover from acute selenium poisoning without any special consequences.

Important!There is no specific antidote for acute selenium poisoning.

Chronic selenium intoxication is not so common, and is mainly associated with living in regions containing excess selenium in soil, water and food. Also, chronic selenium intoxication can occur in industrially undeveloped countries among employees of selenium mining or processing enterprises, when, due to poverty, no one cares about the safety and health of workers.

The main symptoms of chronic excess selenium intake into the body are:

Note! The result of all of the above is the following conclusion. Both excess and deficiency of selenium in the body leads to various pathologies or aggravates the course of existing diseases. That is why it is necessary to ensure that the body receives a strictly necessary dose of selenium.

Selenium has a remarkable feature - its deficiency can be easily corrected with the help of nutrition. To do this, you need to add foods rich in this element to your daily diet.

Three important features should be taken into account:

• When food is thermally processed, the amount of selenium is reduced on average by about half its original level.
• Foods rich in simple carbohydrates (sugars), alcohol, and excessively fatty foods reduce the level of absorbable selenium by almost 4 times.
• The average daily requirement of the body for selenium is 70 – 100 micrograms.

Below is a list of foods containing selenium per 100 grams of raw food, in descending order:

Note: The champion in selenium content is Bertolecia, or Brazil nut - one of its fruits can cover the body's daily need for this element. A certain disadvantage may be the exotic nature and low prevalence of the product for ordinary Russians.

Our usual products containing selenium are:

• poultry (turkey, duck, chicken) 70-55 mcg and animals (pork, lamb, beef) – 55-40 mcg, and poultry meat contains more selenium;
• seafood (fish, shrimp, squid and more exotic lobsters, octopus, crabs) – 50-35 mcg;
• chicken eggs - 32 mcg;
• grains and legumes – corn, rice, beans, lentils – 30-20 mcg;
• pistachios – 19 mcg;
• peas - 13 mcg;
• common nuts – peanuts, walnuts, hazels, almonds – 7-2.5 mcg;
• vegetables and fruits - up to maximum 2 mcg.

As you can see, a varied diet, even without special correction, can meet the body's needs for selenium. Moreover, calculating the number of necessary products is very simple.

A state of selenium deficiency or excess can be established if disorders are suspected and confirmed by appropriate special biochemical tests. If the element is insufficient, correction is carried out with diet and, in the case of laboratory-proven ineffectiveness of the diet, drugs containing selenium may be prescribed.

DEFINITION

Selenium located in the fourth period of group VI of the main (A) subgroup of the Periodic table.

Refers to elements p-families. Non-metal. Designation - Se. Serial number - 34. Relative atomic mass - 78.96 amu.

Electronic structure of the selenium atom

The selenium atom consists of a positively charged nucleus (+34), inside of which there are 34 protons and 45 neutrons, and 34 electrons move around in three orbits.

Fig.1. Schematic structure of a selenium atom.

The distribution of electrons among orbitals is as follows:

34Se) 2) 8) 18) 6 ;

1s 2 2s 2 2p 6 3s 2 3p 6 3d 10 4s 2 4p 4 .

The outer energy level of the selenium atom contains 6 electrons, which are valence electrons. The energy diagram of the ground state takes the following form:

Each valence electron of a selenium atom can be characterized by a set of four quantum numbers: n(main quantum), l(orbital), m l(magnetic) and s(spin):

Sublevel

The presence of two unpaired electrons indicates that the oxidation state of selenium is +2. Since at the fourth level there are vacant orbitals 4 d-sublevel, then the selenium atom is characterized by the presence of an excited state:

That is why selenium also has an oxidation state of +4.

Examples of problem solving

EXAMPLE 1

Selenium (lat. Selenium)– an element of non-metallic origin. In its pure form, it is a solid gray-black substance with a metallic sheen (see photo), which is quite fragile. In another modification (unstable), its color becomes reddish. Under normal conditions it is quite stable, interacts with halogens (chlorine and fluorine), and at elevated temperatures - with oxygen.

The name has Greek roots and comes from the word “Moon”. The reason for this was that in natural conditions this element is a satellite of tellurium, and it is named after the planet Earth. Accordingly, by analogy, he was given the name of the planet’s satellite.

The element was discovered in 1817 by Berzelius from sulfuric acid precipitation.

Selenium is actively used in industry due to its electrical conductivity properties. Although it is found quite rarely in nature, almost never in the form of minerals.

The action of selenium and its biological role

The effect of the macronutrient on the human body has been recognized and studied since 1973. Since that time, the whole world has been gripped by real “selenomania.” Then it seemed that the use of this element would become a panacea for all diseases, and they began to prescribe it in large doses to everyone. But as it turns out, selenium can be both a miracle cure and poison, if not used in moderation.

Selenium has a very powerful effect on almost all activities of our body and plays the following biological role:

In general, there is not a single area in the body that is not affected by selenium. It is part of most enzymes and proteins, and they, in turn, carry out redox reactions and neutralize free radicals, which cause harm at all levels of the body. Selenium binds and removes heavy metal salts (mercury, manganese, cadmium, lead) from the body.

The most important effect of the element is, of course, the fight against cancer and the body’s immune defense against a wide variety of viruses: hepatitis, Ebola, HIV/AIDS. The latter disease is not yet curable, but the element is quite capable of keeping it in a latent state. Selenium traps the virus within the cell; when the supply of the element is depleted, the virus spreads to healthy cells. Its effect on the production of thyroxine, the thyroid hormone, is also important, the deficiency of which causes the growth of this organ. Taking selenium in combination with iodine, with an already developed disease, can cause at least a suspension, or even regression of the disease. The latter is more likely in children.

Selenium also affects the growth of pancreatic cells and insulin-producing cells. In this case, glucose consumption accelerates, which is a good prevention or treatment for the development of diabetes mellitus. In the gastrointestinal tract, with the participation of the macroelement, the microflora is normalized, damaged tissues and mucous are regenerated. Bile formation in the liver is stabilized, which improves its functioning.

Don't forget about selenium during pregnancy. After all, it will help fight toxicosis and give you a good mood, relieving all the symptoms of anxiety. During feeding, it is also necessary, and in double quantities, because the baby receives all the elements with mother’s milk.

The element itself is not a guaranteed cure, but a comprehensive, qualified approach can help in most cases. Prophylactic use will significantly reduce all risks of acquiring the above diseases. But, in any case, self-medication is not recommended.

Daily norm - what is the body's need for a chemical element?

The daily macronutrient requirement is determined by the World Health Organization within the following limits:

• adults (woman/man) – 55-70 mcg;
• infants under 1 year - 10-15 mcg;
• preschool children – 20 mcg;
• children of primary school age and adolescents – 30-50 mcg;
• pregnant and lactating women – 65-200 mcg;
• athletes, on the other hand, need up to 200 mcg of the substance.

The maximum dose is considered to be 400 mcg per day. Loading doses are prescribed only when a significant deficiency is diagnosed under the close supervision of doctors.

Selenium deficiency - symptoms of deficiency and characteristics of its harm to health

A deficiency of a macronutrient can cause so-called “diseases of civilization,” despite the fact that for a long time it was considered a real poison. The consequences of deficiency can be extremely disappointing and harmful to health, in particular, they manifest themselves in the following symptoms:

The tendency to develop a deficiency increases with age, and accordingly, the tendency to disease also increases. Recently, it has been noticed that there is a sharp increase in the number of the above-mentioned diseases, and they are becoming more chronic and aggressive. These processes are associated with the deterioration of lifestyle and the environment. Our food today is too poor in useful elements and vitamins, because... grown on depleted lands. Fertilizers, poisoning of soils and soils with industrial waste affect the chemical composition of products.

Excess selenium in the body

As already mentioned, selenium can also be poisonous. Although its effect on the body is invaluable, too little of it is required - about a hundred thousandth of one gram.

Exceeding doses will quickly affect your health and appearance, causing the following symptoms: weak nails and hair, muscle pain, redness or flaking of the skin, dental problems, dysfunction of the nervous system, kidneys, liver, decreased immunity.

Most often, an excess of the element occurs in people who earn money by extracting this element during the development of natural strata, as well as in residents of settlements bordering the mining sites. Also, uncontrolled use of drugs in pursuit of a magical cure for cancer causes excess. Although it has been proven that a large amount of selenium can have the opposite effect, that is, it can accelerate the growth of tumors and interfere with the effect of chemotherapy.

Sources containing this item

Almost the entire population of the planet suffers from mild selenium deficiency - they receive about 70-80%. And only residents of coastal areas receive the required amount of the element by consuming seafood rich in it.

It is quite possible to maintain the required level of the element in the body with food. The main thing is to know what to eat! It will be enough to add dairy products, lard, veal, legumes and coconuts to the diet. A certain amount of it can be found in rock or sea salt, eggs, bran, tomato, corn, and wholemeal products. But all these products should be eaten fresh, without processing (preservation, concentration), because... it completely destroys selenium, and heat treatment reduces the amount of the useful element by half.

There are several products that can be called leaders in selenium content. This is broccoli, oregano, garlic and yeast. True, everything that follows concerns products grown on environmentally friendly lands.

Brewer's and baker's yeast are a wonderful source of selenium, because here it is in a biologically active form and is easily absorbed. In the middle of the 20th century, it was found that the use of yeast prevented or even stopped the development of liver necrosis. It turned out that our macronutrient was the mysterious component. The only thing is that the yeast must be processed before use, otherwise there will be little benefit from it.

Why? As you know, this substance is a living organism and even in the body it continues to feed, mainly with B vitamins, and specifically biotin. The same, in turn, affects the immune system. Therefore, it is necessary to extinguish the activity of the yeast, and for this you need to treat it with hot water (at least 60 degrees Celsius). There is no need to get carried away - two grams per day is more than enough for a healthy person. For everyone else, the doctor will determine the norm and the course of treatment most often lasts no more than 2 weeks.

You can correct selenium deficiency with garlic. It is the garlic smell that appears when there is an overdose of the element. In addition to selenium, you will receive a lot of useful substances: proteins, carbohydrates, minerals, vitamins B and C. And the smell is nothing more than allicin (a sulfur compound with an unpleasant odor characteristic of garlic), which kills bacteria. Please note that preparations with supposedly garlic extracts do not have the properties of a natural product.

Italian and Spanish cuisines are rich in the presence of garlic, and it has long been noted that people living in these countries are much less likely to suffer from heart disease, atherosclerosis and senile insanity. And eating them with meat slightly neutralizes the effect of fats and cholesterol.

Brazil nuts can be added to the list of selenium-containing foods. They grow on tropical soils rich in selenium, and one nut can replace the entire daily requirement of the element for an adult. But this amount (up to 100 mcg) is found only in unshelled nuts. Kernels without shells contain 4-5 times less of the element.

Selenium deficiency in infants, namely boys, can most often be explained by artificial nutrition. After all, mother's milk contains twice as much selenium and 5 times more vitamin E than cow's milk. The male sex needs more of the element, and the deficiency is more pronounced. Many doctors associate the mysterious “sudden death” of newborns with a lack of these two substances.

Interaction with other substances

The presence of certain elements and vitamins helps selenium cope with diseases. For example, vitamins E and C, combined with selenium, fight viruses, infections and cancer. Together with cobalt and magnesium, it affects the protection of chromosomes and genetic material in cells.

The enemy, with full confidence, can be called carbohydrates, which are capable of completely destroying all accumulations of selenium in the body. So all the cakes and pastries have once again proven their incompetence.

There is one more substance that can be called an enemy of the beneficial element. This is a mold that has a carcinogenic effect on cells. It can enter the body through food containing rotting grain or potatoes stored in damp rooms.

Indications for use

Indications for prescribing a macroelement are determined by its biological effect on the human body. It serves as a prophylactic for many diseases that are caused by its deficiency. Main purposes:

• thyroid dysfunction;
• multiple sclerosis;
• abnormalities of fetal development and pregnancy;
• treatment of pancreatitis;
• skin diseases (psoriasis, lichen, dermatitis) - used for internal and external use.

When choosing medications, pay close attention to some points. For example, the content of the element in additives. There was a known case when one of the manufacturers placed 100 mg of an element in the drug instead of 100 mcg. It turned out that consumers for some time exceeded the norm by 1000 times, which naturally led to multiple poisonings. Don't forget that you will also get some from food.

There are also medications that contain inorganic selenium compounds, which can cause side effects such as nausea and stomach discomfort. It would be better to use medications with easily digestible organic compounds.