Exchange of water proteins and mineral salts. Exchange of water and mineral salts

The body needs a constant supply of not only water, but also mineral salts. They enter the body with food and water, with the exception of table salt, which is specially added to food. In total, about 70 chemical elements were found in the body of animals and humans, of which 43 are considered indispensable (essential; lat. essentia - essence).

The body's need for various minerals is not the same. Some elements called macronutrients, are introduced into the body in a significant amount (in grams and tenths of a gram per day). Macroelements include sodium, magnesium, potassium, calcium, phosphorus, chlorine. Other elements - trace elements(iron, manganese, cobalt, zinc, fluorine, iodine, etc.) are needed by the body in extremely small quantities (in micrograms - thousandths of a milligram).

Functions of mineral salts:

1) are biological constants of homeostasis;

2) create and maintain osmotic pressure in the blood and tissues (osmotic balance);

3) maintain the constancy of the active reaction of the blood

(pH=7.36 - 7.42);

4) participate in enzymatic reactions;

5) participate in water-salt metabolism;

6) sodium, potassium, calcium, chlorine ions play an important role in the processes of excitation and inhibition, muscle contraction, blood clotting;

7) are an integral part of bones (phosphorus, calcium), hemoglobin (iron), the hormone thyroxine (iodine), gastric juice (hydrochloric acid), etc.;

8) are integral components of all digestive juices, which are excreted in large quantities.

Consider briefly the exchange of sodium, potassium, chlorine, calcium, phosphorus, iron and iodine.

1) Sodium enters the body mainly in the form of table (table) salt. It is the only mineral salt that is added to food. Plant foods are poor in table salt. The daily requirement for table salt for an adult is 10-15 g. Sodium is actively involved in maintaining osmotic balance and fluid volume in the body, and affects the growth of the body. Together with potassium, sodium regulates the activity of the heart muscle, significantly changing its excitability. Symptoms of sodium deficiency: weakness, apathy, muscle twitching, loss of muscle contractility properties.

2) Potassium enters the body with vegetables, meat, fruits. Its daily norm is 1 g. Together with sodium, it participates in the creation of a bioelectric membrane potential (potassium-sodium pump), maintains the osmotic pressure of the intracellular fluid, and stimulates the formation of acetylcholine. With a lack of potassium, inhibition of the processes of assimilation (anabolism), weakness, drowsiness, hyporeflexia (decrease in reflexes) is observed.

3) Chlorine enters the body in the form of salt. Chlorine anions, together with sodium cations, are involved in creating the osmotic pressure of blood plasma and other body fluids. Chlorine is also part of the hydrochloric acid of gastric juice. There are no symptoms of chlorine deficiency in humans.

4) Calcium enters the body with dairy products, vegetables (green leaves). It is contained in the bones along with phosphorus and is one of the most important biological constants of the blood. The calcium content in human blood is normally 2.25-2.75 mmol / l (9-11 mg%). A decrease in calcium leads to involuntary muscle contractions (calcium tetany) and death due to respiratory arrest. Calcium is essential for blood clotting. The daily requirement for calcium is 0.8 g.

5) Phosphorus enters the body with dairy products, meat, cereals. The daily requirement for it is 1.5 g. Together with calcium, it is found in bones and teeth, it is part of high-energy compounds (ATP, creatine phosphate, etc.). The deposition of phosphorus in the bones is possible only in the presence of vitamin D. With a lack of phosphorus in the body, bone demineralization is observed.

6) Iron enters the body with meat, liver, beans, dried fruits. The daily requirement is 12-15 mg. It is an integral part of blood hemoglobin and respiratory enzymes. The human body contains 3 g of iron, of which 2.5 g is found in erythrocytes as an integral part of hemoglobin, the remaining 0.5 g are part of the cells of the body. Iron deficiency disrupts the synthesis of hemoglobin and, as a result, leads to anemia.

7) Iodine comes with drinking water enriched with it when flowing through rocks or with table salt with the addition of iodine. The daily requirement is 0.03 mg. Participates in the synthesis of thyroid hormones. Lack of iodine in the body leads to endemic goiter - an increase in the thyroid gland (some areas of the Urals, the Caucasus, the Pamirs, etc.).

Violation of mineral metabolism can lead to a disease in which stones of different sizes, structure and chemical composition are formed in the renal cups, pelvis and ureters (nephrolithiasis). It can also contribute to the formation of stones in the gallbladder and bile ducts (cholelithiasis).

Importance of water and salts. All transformations of substances in the bodytake place in the aquatic environment. dissolves food that has entered the body. Together with minerals, it takes part in the construction of cells and in many metabolic reactions.

Participates in the regulation of body temperature; evaporating, it cools the body, protecting it from overheating; transports dissolved.

And mineral salts create mainly the internal environment of the body, being the main component of blood plasma, lymph and tissue fluid. They are involved in maintaining the osmotic pressure and the reaction of blood plasma and tissue fluid. Some salts dissolved in the liquid part of the blood are involved in the transport of gases by the blood.

Water and mineral salts are part of the digestive juices, which largely determines their importance for the digestive process. And although neither water nor mineral salts are sources of energy in the body, their normal intake and removal from the body is a condition for its normal activity. Suffice it to point out that water in an adult is approximately 65% ​​of body weight, and in children - about 80%.

Depriving a person of water for several days is fatal.

Loss of water by the body leads to very severe disorders. For example, in case of indigestion in infants, the most dangerous is dehydration, which leads to convulsions and loss of consciousness.

body water exchange

Replenishment of the body with water occurs constantly due to its absorption from the digestive tract. A person needs 2-2.5 liters of water per day with a normal diet and normal ambient temperature. This amount of water comes from the following sources: 1) drinking water (about 1 liter); 2) water contained in food (about 1 liter); 3) water, which is formed in the body during the metabolism of proteins, fats and carbohydrates (300-350 cm 3).

The main organs that remove water from the body are the kidneys, sweat glands, lungs and intestines. The kidneys remove 1.2-1.5 liters of water from the body per day as part of the urine. Sweat glands remove 500-700 cm 3 of water per day through the skin in the form of sweat. At normal temperature and air humidity, about 1 mg of water is released per 1 cm 2 of the skin every 10 minutes.

The lungs in the form of water vapor excrete 350 cm 3 of water. This amount increases sharply with deepening and quickening of breathing, and then 700-800 cm 3 of water can stand out per day. Through the intestines with feces, 100-150 cm 3 of water is excreted per day. With a disorder in the activity of the intestines, more water can be excreted in the feces (with diarrhea), which leads to depletion of the body with water. For the normal functioning of the body, it is important that the flow of water into the body completely covers its consumption.

The ratio of the amount of water consumed to the amount allocated is water balance.

If more water is excreted from the body than it enters, there is a feeling of thirst. As a result of thirst, a person drinks water heavily.

salt metabolism in the body

With the exclusion of animal minerals from the diet, severe disorders in the body and even death occur. The presence of minerals is associated with the phenomenon of excitability - one of the main properties of living things. The growth and development of bones, nerve elements, muscles depend on the content of minerals. They determine the reaction of the blood (pH), contribute to the normal functioning of the heart and nervous system, are used to form hemoglobin (), hydrochloric acid of gastric juice ().

Mineral salts create a certain, so necessary for the life of cells.

With a mixed diet, an adult receives all the minerals he needs in sufficient quantities. Only table salt is added to human food during its culinary processing. A growing child's body especially needs an additional intake of many minerals.

Minerals have an important influence on the development of the child. The growth of bones, the timing of cartilage ossification, and the state of oxidative processes in the body are associated with the exchange of calcium and phosphorus. With insufficient intake of calcium from food or depletion of the body for some reason, the bone tissue gives in to maintain homeostasis in it. affects the excitability of the nervous system, blood clotting, protein and fat metabolism in the body. is needed not only for the growth and development of bone tissue, but also for the normal functioning of the nervous system, most glandular and other organs.

It is an integral part of blood hemoglobin.

The body constantly loses a certain amount of mineral salts in urine, sweat and feces. Therefore, mineral salts, like water, must constantly enter the body. The content of individual elements in the human body is not the same (Table 18),

Table 18

The content of elements in the human body

Regulation of water-salt metabolism

Osmotic constancyThe pressure of the internal environment of the body, determined by the content of water and salts, is regulated by the body.

With a lack of water in the body, tissue fluid increases. This leads to irritation of special receptors located in the tissues - osmoreceptors. Impulses from them are sent along special nerves to the brain to the center of regulation of water-salt metabolism. From there, the excitation goes to the endocrine gland - the pituitary gland, which secretes into a special hormone that causes urinary retention. Reducing the excretion of water in the urine restores the disturbed balance. This example clearly shows the interaction of nervous and humoral mechanisms of regulation of physiological functions.

Metabolism of matter and energy, the concept of intermediate exchange. Enzymes.

Metabolism (syn.: metabolism) - the totality of all chemical transformations in the body that ensure its vital activity. There are two aspects of metabolism - assimilation, during which the body synthesizes substances specific to it, and dissimilation, during which splitting (oxidation) of organic substances occurs and the energy contained in them is released.

Energy exchange. It is typical for a person to convert the chemical energy of oxidative processes into thermal and mechanical energy of the formation of the most complex organic molecules. By consuming food and oxygen, the body uses these substances to obtain energy, which it then releases into the surrounding space in the form of heat or in the form of mechanical movements of objects or parts of its own body.

Enzymes (lat. fermentum - fermentation, fermentation) - complex proteins of animal and plant organisms that act as biological catalysts, accelerating chemical reactions and metabolism in cells.

Distinguish between the general (external) metabolism, taking into account the intake of substances into the body and their excretion, and intermediate metabolism , which covers the transformation of these substances in the body.

Metabolism of proteins, fats, carbohydrates, water, mineral salts.

From the textbook:

Protein metabolism- a set of chemical transformations of proteins in the body, ending with their breakdown to water, carbon dioxide, ammonia and the release of the energy contained in them. Proteins are used by the body to renew and

building new tissues, enzymes, are an energy source. When splitting 1 g of protein, 4.1 kcal of energy is released.

Fat metabolism- a set of chemical transformations of fats in the body, ending with their breakdown (to water and carbon dioxide) and the release of energy. Fats are used by the body to renew and build new tissues, enzymes, hormones, as well as to obtain the energy needed by the body.

When splitting 1 g of fat, 9.3 kcal of energy is released.

Exchange of mineral salts- a set of processes of consumption, use of mineral salts in the body and their release into the environment. Mineral salts are used in the body to maintain osmotic pressure, acid-base balance (pH) of the blood, are part of enzymes, vitamins, hormones.

Carbohydrate metabolism- a set of chemical transformations of carbohydrates in the body, ending in their breakdown and release of energy. Carbohydrates are the body's main energy source. When splitting 1 g of carbohydrates, 4.1 kcal of energy is released.

From the Internet, because I thought that the textbook is not enough:

Protein metabolism. Proteins make up about 25% of the total body weight. This is the most difficult part of it. Proteins are polymeric compounds made up of amino acids. The protein set of each person is strictly unique, specific. In the body, food protein is broken down by digestive juices into its simple components - peptides and amino acids, which are then absorbed in the intestines and enter the bloodstream. Of the 20 amino acids, only 8 are indispensable for humans. These include: tryptophan, leucine, isoleucine, valine, threonine, lysine, methionine, and phenylalanine. A growing organism also needs histidine.

The absence of any of the essential amino acids in food causes serious disturbances in the vital activity of the organism, especially when it is growing. Protein starvation leads to a delay, and then to a complete cessation of growth and physical development. The child becomes lethargic, there is a sharp weight loss, profuse swelling, diarrhea, inflammation of the skin, anemia, a decrease in the body's resistance to infectious diseases, etc. This is due to the fact that protein is the main plastic material of the body, from which various cellular structures are formed. In addition, proteins are part of enzymes, hormones, nucleoproteins, form hemoglobin and blood antibodies.

If the work is not associated with intense physical activity, the human body on average needs to receive about 1.1-1.3 g of protein per 1 kg of body weight per day. As physical activity increases, so does the body's need for protein. For a growing organism, the need for protein is much higher. In the first year of postnatal development, a child should receive more than 4 g of protein per 1 kg of body weight, at 2-3 years old - 4 g, at 3-5 years old - 3.8 g, etc.

Metabolism of fats and carbohydrates. These organic substances have a simpler structure, they consist of three chemical elements: carbon, oxygen and hydrogen. The same chemical composition of fats and carbohydrates allows the body to build fats from them with an excess of carbohydrates, and, conversely, if necessary, carbohydrates are easily formed from fats in the body.

The total amount of fat in the human body is on average about 10-20%, and carbohydrates - 1%. Most of the fat is in adipose tissue and is a reserve energy reserve. A smaller part of fats is used to build new membrane structures of cells and to replace old ones. Some cells of the body are able to accumulate fat in large quantities, performing the role of thermal and mechanical insulation in the body.

In the diet of a healthy adult, fats should make up about 30% of the total calorie content of food, i.e. 80-100 g per day. Inadequate intake of these fatty acids in the human body leads to metabolic disorders and the development of atherosclerotic processes in the cardiovascular system.

The needs of children and adolescents in fats have their own age characteristics. So, up to 1.5 years there is no need for vegetable fats, and the total need is 50 g per day, from 2 to 10 years the need for fats increases 80 g per day, and for vegetable fats - up to 15 g, during puberty the need for fat in boys is 110 g per day, and in girls - 90 g, and the need for vegetable fats in both sexes is the same - 20 g per day.

Carbohydrates in the body are broken down to glucose, fructose, galactose, etc. and then absorbed into the blood. The content of glucose in the blood of an adult is constant and equals an average of 0.1%. With an increase in the amount of sugar in the blood to 0.11-0.12%, glucose enters from the blood to the liver and muscle tissues, where it is deposited in the form of animal starch - glycogen. With a further increase in blood sugar to 0.17%, the kidneys are included in its excretion from the body, and sugar appears in the urine. This phenomenon is called glycosuria.

The body uses carbohydrates mainly as an energy material. So, up to 1 year the need for carbohydrates is 110 g per day, from 1.5 to 2 years - 190 g, at 5-6 years old - 250 g, at 11-13 years old - 380 g and in young men - 420 g, and for girls - 370 g. In the children's body, there is a more complete and rapid absorption of carbohydrates and greater resistance to excess sugar in the blood.

Salt exchange. With the exclusion of animal minerals from the diet, severe disorders in the body and even death occur. The presence of minerals is associated with the phenomenon of excitability - one of the main properties of living things. The growth and development of bones, nerve elements, muscles depend on the content of minerals; they determine the reaction of the blood (pH), contribute to the normal functioning of the heart and nervous system, are used to form hemoglobin (iron), hydrochloric acid of gastric juice (chlorine).

Mineral salts create a certain osmotic pressure, which is so necessary for the life of cells.

With a mixed diet, an adult receives all the minerals he needs in sufficient quantities. Only table salt is added to human food during its culinary processing. A growing child's body especially needs an additional intake of many minerals.

The body constantly loses a certain amount of mineral salts in urine, sweat and feces. Therefore, mineral salts, like water, must constantly enter the body. The content of individual elements in the human body is not the same.

Water exchange. For the vital activity of the body, water plays a much greater role than other components of food. The fact is that water in the human body is both a building material, a catalyst for all metabolic processes and a temperature regulator of the body. The total amount of water in the body depends on age, sex and weight. On average, a man's body contains over 60% of water, while a woman's body contains 50%.

The water content in the child's body is much higher, especially in the early stages of development. According to embryologists, the water content in the body of a 4-month-old fetus reaches 90%, and in a 7-month-old fetus it is 84%. In the body of a newborn, the volume of water is from 70 to 80%. In postnatal ontogenesis, the water content drops rapidly. So, the child is 8 months old. the water content is 60%, in a 4.5-year-old child - 58%, in boys of 13 years - 59%, and in girls of the same age - 56%. The higher water content in the body of children is obviously associated with a greater intensity of metabolic reactions associated with their rapid growth and development. The total water requirement of children and adolescents increases as the body grows. If a one-year-old child needs about 800 ml of water per day, then at 4 years old - 1000 ml, at 7-10 years old - 1350 ml, and at 11-14 years old - 1500 ml.

All transformations of substances in the body occur in the aquatic environment. Water dissolves the nutrients that enter the body. Together with minerals, it takes part in the construction of cells and in many metabolic reactions.

Water is involved in the regulation of body temperature; evaporating, cools the body, protecting it from overheating; transports dissolved substances.

Water and mineral salts create mainly the internal environment of the body, being the main component of blood plasma, lymph and tissue fluid. They are involved in maintaining osmotic pressure and the reaction of blood plasma and tissue fluid. Some salts dissolved in the liquid part of the blood are involved in the transport of gases by the blood.

Water and mineral salts are part of the digestive juices, which largely determines their importance for the digestive process. And although neither water nor mineral salts are sources of energy in the body, their entry into the body and removal from there are a prerequisite for its normal activity.

Loss of water by the body leads to very severe disorders. For example, in case of indigestion in infants, the most dangerous is dehydration, which leads to convulsions, loss of consciousness, etc. It is the sharp dehydration of the body due to loss of fluid that causes such a severe course of such an infectious disease as cholera. Deprivation of water for several days is fatal to humans.

Water exchange

Replenishment of the body with water occurs constantly due to its absorption from the digestive tract. A person needs 2-2.5 liters of water per day with a normal diet and normal ambient temperature. This amount of water comes from the following sources: a) drinking water (about 1 liter); b) water contained in food (about 1 liter); c) water, which is formed in the body during the metabolism of proteins, fats and carbohydrates (300-350 ml).

The main organs that remove water from the body are the kidneys, sweat glands, lungs and intestines. The kidneys remove 1.2-1.5 liters of water from the body per day as part of the urine. Sweat glands remove 500-700 ml of water per day through the skin in the form of sweat. At normal temperature and air humidity, about 1 mg of water is released per 1 cm2 of the skin every 10 minutes. In the deserts of the Arabian Peninsula, however, a person daily loses about 10 liters of water through sweat. During intensive work, a lot of fluid is also released in the form of sweat: for example, in two halves of a tense football match, a football player loses about 4 liters of water.

The lungs in the form of water vapor remove 350 ml of water. This amount increases sharply with deepening and quickening of breathing, and then 700-800 ml of water can be released per day.

Through the intestines with feces, 100-150 ml of water is excreted per day. With a disorder of the activity of the intestine with feces, a large amount of water can be excreted (with diarrhea), which can lead to depletion of the body with water. For the normal functioning of the body, it is important that the intake of water completely covers its consumption.

The ratio of the amount of water consumed to the amount allocated is water balance.

If more water is excreted from the body than it enters, then there is a feeling thirst. As a result of thirst, a person drinks water until normal water balance is restored.

Salt exchange

With the exclusion of animal minerals from the diet, severe disorders in the body and even death occur. The presence of minerals is associated with the phenomenon of excitability - one of the main properties of living things. The growth and development of bones, nerve elements, muscles depend on the content of minerals; they determine the reaction of the blood (pH), contribute to the normal functioning of the heart and nervous system, are used to form hemoglobin (iron), hydrochloric acid of gastric juice (chlorine).

Mineral salts create a certain osmotic pressure, which is so necessary for the life of cells.

With a mixed diet, an adult receives all the minerals he needs in sufficient quantities. Only table salt is added to human food during its culinary processing. A growing child's body especially needs an additional intake of many minerals.

The body constantly loses a certain amount of mineral salts in urine, sweat and feces. Therefore, mineral salts, like water, must constantly enter the body. The content of individual elements in the human body is not the same (Table 13).

Regulation of water-salt metabolism

The constancy of the osmotic pressure of the internal environment of the body, determined by the content of water and salts, is regulated by the body.

With a lack of water in the body, the osmotic pressure of the tissue fluid increases. This leads to irritation of special receptors located in the tissues - osmoreceptors. Impulses from them are sent along special nerves to the brain to the center of regulation of water-salt metabolism. From there, the excitation is sent to the endocrine gland - the pituitary gland, which releases a special hormone into the bloodstream that causes urinary retention. Reducing the excretion of water in the urine restores the disturbed balance.

This example clearly shows the interaction of nervous and humoral mechanisms of regulation of physiological functions. The reflex begins nervously with osmoreceptors, and then the humoral mechanism is activated - the entry of a special hormone into the blood.

The center of regulation of water-salt metabolism controls all ways of transporting water in the body: its excretion with urine, sweat and through the lungs, redistribution between body organs, absorption from the digestive tract, secretion, and water consumption. Particularly important in this regard are certain parts of the diencephalon. If electrodes are introduced into these areas of an animal, and then the brain is irritated with an electric current through them, then the animals begin to drink water voraciously. In this case, the amount of water drunk can exceed 40% of body weight. As a result, there are signs of water poisoning associated with a decrease in the osmotic pressure of blood plasma and tissue fluid. Under natural conditions, these centers of the diencephalon are under the controlling influence of the cerebral cortex.

The mechanism of water balance regulation is very important in practical life. In cases where water has to be saved, in no case should it be drunk in one gulp, but always in very small sips. You will feel that you are drunk, although you have drunk a little water. Knowledge of the features of the regulation of water-salt metabolism is important in one more case. In hot weather, you are usually very thirsty, and no matter how much water you drink, you are still thirsty. But it is worth consciously enduring a little, despite the feeling of thirst, and it passes. That is why you should not drink a lot in the heat, on a hike, etc. The correct tactic here is this: knowing that you have a difficult hike or a long stay in the sun, it is better to drink water “in reserve” in advance, at a time when you still don’t feel like drinking . In this case, then there is no such strong feeling of thirst as if you started drinking in the heat.

Two more practical tips. Before setting off on a hike, you should drink mineral or salted water or eat some moderately salty food - feta cheese, salted cheese, etc. - and drink it well with water. The fact is that a lot of salts are lost with sweat, and this leads to an increase in fatigue, muscle weakness, etc. You also need to know that “false thirst” often occurs in the heat: you want to drink not because there is little fluid in the body, and due to the drying of the oral mucosa. In this case, simply rinse your mouth with water.

The human body is 60% water. Adipose tissue contains 20% water (of its mass), bones - 25%, liver - 70%, skeletal muscles - 75%, blood - 80%, brain - 85%.

For the normal functioning of an organism that lives in a changing environment, the constancy of the internal environment of the organism is very important. It is created by blood plasma, tissue fluid, lymph, the main part of which is water, proteins and mineral salts. Water and mineral salts do not serve as nutrients or energy sources. But without water, metabolic processes cannot proceed. Water performs the following important functions in the body: 1) serves as a solvent for food and metabolism; 2) transfers substances dissolved in it; 3) weakens the friction between the contacting surfaces in the human body; 4) participates in the regulation of body temperature due to high thermal conductivity, high heat of evaporation.

Without water, a person can live no more than 7-10 days, while without food, 30-40 days. Water is removed along with urine through the kidneys (1700 ml), with sweat through the skin (500 ml) and with air exhaled through the lungs (300 ml).

The ratio of the total fluid intake to the total fluid excreted is called water balance .

Water enters the human body in a “pure form” and as part of various products, with which it also receives the elements it needs. daily human need for water leaves 2.0 - 2.5 liters. The daily need of the human body for some trace elements is as follows: potassium 2.7 - 5.9 g, sodium 4 - 5 g, calcium 0.5 g, magnesium 70 - 80 mg, iron 10 - 15 mg, manganese - up to 100 mg, chlorine 2-4 g, iodine 100 - 150 mg.

It is customary to divide water into intracellular, intracellular (72%) and extracellular, extracellular (28%). Extracellular water is located inside the vascular bed (in the composition of blood, lymph, cerebrospinal fluid) and in the intercellular space.

With an excess of water in the body, general hyperhydration (water poisoning) is observed, with a lack of water, metabolism is disturbed. Loss of 10% of water leads to a state of dehydration (dehydration), with a loss of 20% of water, death occurs.

Minerals are part of the skeleton, the structure of proteins, hormones, enzymes. The total amount of all minerals in the body is approximately 4-5% of body weight. A person receives the main part of minerals with food and water. However, their content in food is not always enough. Most people have to add, for example, sodium chloride (NaCL - table salt) to food at 10 - 12 g per day. A chronic lack of minerals in food can lead to a breakdown in body functions.

Sodium ensures the constancy of the osmotic pressure of the extracellular fluid, participates in the creation of a bioelectric membrane potential, in the regulation of the acid-base state.

Potassium provides osmotic pressure of intracellular fluid, stimulates the formation of acetylcholine. The lack of potassium ions inhibits anabolic processes in the body.

Chlorine is also the most important anion of the extracellular fluid, ensuring the constancy of osmotic pressure.

calcium and phosphorus are found mainly in bone tissue (over 90%). The content of calcium in plasma and blood is one of the biological constants, since even slight changes in the level of this ion can lead to severe consequences for the body. A decrease in blood calcium levels causes involuntary muscle contractions, convulsions, and death occurs due to respiratory arrest. An increase in the calcium content in the blood is accompanied by a decrease in the excitability of the nervous and muscle tissues, the appearance of paresis, paralysis, and the formation of kidney stones. Calcium is necessary for building bones, so it must be supplied in sufficient quantities in the body with food.

Phosphorus participates in the metabolism of many substances, as it is part of high-energy compounds (for example, ATP). Of great importance is the deposition of phosphorus in the bones.

Iron is part of hemoglobin, myoglobin, responsible for tissue respiration, as well as in the composition of enzymes involved in redox reactions. Insufficient intake of iron in the body disrupts the synthesis of hemoglobin. A decrease in hemoglobin synthesis leads to anemia (anemia). The daily iron requirement for an adult is 10--30 mcg.

Iodine in the body is contained in a small amount. However, its significance is great. This is due to the fact that iodine is part of the thyroid hormones, which have a pronounced effect on all metabolic processes, growth and development of the body.

Vitamins (lat. vita - life). The importance of vitamins lies in the fact that being present in the body in negligible amounts, they regulate metabolic reactions. With a lack of vitamins in the body, a condition called hypovitaminosis develops.

A disease that occurs in the absence of a particular vitamin is called beriberi.

To date, more than 20 substances have been discovered that are related to vitamins:

Vitamin A With avitaminosis A, the growth processes of the body are delayed, metabolism is disturbed, and a special eye disease called xerophthalmia (night blindness) is also observed.

Vitamin D called the anti-rachitic vitamin. Its deficiency leads to a disorder of phosphorus and calcium metabolism.

Vitamin B The lack of these vitamins leads to metabolic disorders, disorders of the central nervous system. This reduces the body's resistance to infectious diseases.

Vitamin C called antiscorbutic. With a lack of it in food (and most of all it is found in fresh fruits and vegetables), a specific disease develops - scurvy, in which the gums bleed, and the teeth loosen and fall out. Physical weakness, fatigue, nervousness develop.

Vitamin E and K- are important for the body and are known vitamins.