Modern scientific data on the effect of minerals and vitamins on physical performance suggest that with normal provision of the body with vitamins and minerals, maximum working capacity is achieved. The use of megadoses of vitamins or minerals has no additional advantages over the normal provision of the body.
Intensive physical activity, of course, increases the need for vitamins and minerals. But this need is met with proper nutrition by increasing the amount of food consumed necessary to cover the athlete’s energy needs. Given the violations and deficiencies of athletes’ nutrition, additional use of multivitamin and mineral supplements should be used. However, the doses of vitamins and minerals used should be commensurate with the physiological daily requirement for these nutrients. Once again, we emphasize that there is no scientific evidence that the consumption of large amounts of vitamins and minerals, which dozens and hundreds of times exceed daily requirements, does not give any advantages in working capacity and improving sports results in any sports.
The use of moderate doses of vitamin or mineral preparations is due to the need to prevent scarce conditions and meet the increased demand for a number of minerals and vitamins.
As a component of hemoglobin and myoglobin, iron plays a crucial role in the acceptance and transfer of oxygen in muscle tissue. Myoglobin acts in the muscle as an acceptor of oxygen, transmitting it to the mitochondria. Iron is also a component of cytochrome respiratory chain, in which ATP is generated.
Iron deficiency anemia manifests itself in a significant reduction in the physical performance of any person, especially the athlete, from whom the maximum performance is required. Depletion of the iron depot in the liver, spleen and bone marrow, which is diagnosed by reducing the concentration of ferritin in the blood plasma, has a negative effect on physical performance, even when there are no clinical and laboratory signs of iron deficiency anemia. The content of ferritin in the blood plasma is recommended to be used as a marker of the body’s supply of iron, and its decrease in blood plasma – as a sign of iron deficiency.
The risk of developing iron deficiency is high among teenage sportsmen, both girls and boys, in female athletes with heavy blood loss during menstruation, especially when the caloric intake is low because of the need to reduce or maintain low body weight.
Intensive training loads can sometimes cause transient anemia of athletes, which is characterized by a decrease in the number and volume of red blood cells and the level of hemoglobin in the blood. The structure and functional properties of red blood cells remain normal. The performance of the athlete can not be violated. Transient anemia is caused by dilution of blood, intravascular hemolysis of erythrocytes, loss of iron through the gastrointestinal tract and with sweat. Loss of iron through the gastrointestinal tract is observed quite often in runners for long distances. This phenomenon is diagnosed by the analysis of hemoglobin in feces.
Loss of iron with sweat is observed with intensive loads in a warm environment. The concentration of iron in the sweat with intensive training is 0.13-0.42 mg / l. It is interesting to note that in a hot environment (35 ° C) the concentration of iron in the pot is lower than in a relatively warm medium (25 ° C). But due to the greater amount of perspiration in the hot climate, the total loss of iron was the same with the training load for 1 hour. At the same time, men lose three times more iron than women. The greatest loss of iron with sweat is observed in the first 30 minutes of exercise and sweating.
Enrichment of the diet with iron or iron supplements in the form of drugs increases the depot of iron in the body of athletes with iron deficiency. The appointment of iron to athletes who do not have a deficit, does not affect physical performance. Large doses of iron (more than 70 mg / day) can have a toxic effect, especially with hemo-mochromatosis. The use of iron preparations is justified only for athletes suffering from its deficiency or anemia. When iron deficiency is established, even in the absence of signs of anemia, iron preparations should be used in combination with vitamin C, which improves the absorption of non-heme iron.
Interest in ensuring the need for calcium is associated with its importance in bone formation and ensuring its density and strength. Osteoporosis is a fairly common disease affecting women during menopause. Among the risk factors for osteoporosis are hormonal disorders, primarily estrogen deficiency, insufficient calcium intake and low physical activity.
The increase in bone mass occurs before the age of 35-40 years of age. However, the peak of bone tissue growth is at the age of 14-24 years. Density of bone is formed in adolescence and adolescence. During this period, the highest demand for calcium. It is important at this age and maintenance of an adequate level of physical activity, especially for girls and women. The incidence of fractures of long tubular bones in older women depends on the density and mass of bone tissue achieved by the age of 35 years. Formation at a young age of dense and strong bone tissue with sufficient calcium intake and level of physical activity is the most important factor in preventing osteoporosis in adulthood and old age.
In 1997, the American Council for Sports Medicine formulated the concept of a “pathological triad” in female athletes, which includes estrogen deficiency and amenorrhea, an eating disorder and a decrease in body fat reserves, and a decrease in bone mass. There is a triad of intensively trained women, who develop amenorrhea. The lack of estrogen leads to a loss of bone mass and a decrease in its density and strength. In the treatment of amenorrhea, estrogens are used, an increased intake of calcium, vitamin B, an increase in energy intake and a decrease in intensity of training are recommended.
Recall that the need for calcium can be met only with the necessary consumption of dairy products or products enriched with calcium.
Vitamins of antioxidant action
The performance of intensive physical work increases the oxygen consumption of tissues by 10-15 times compared with the resting state. Increased oxygen consumption is a risk factor for the development of “oxidative stress”, leading to the generation of free oxygen radicals and the induction of lipid peroxidation (LPO). Most studies do not directly fix free radicals in the muscle, but evaluate the effects induced by free radicals, such as the formation of secondary LPO products. These products include malonic dialdehyde and diene conjugates found in the blood, or pentane, released with exhaled air. Particularly pronounced is the effect of physical exertion on the formation of LPO products in untrained people.
In the body there are antioxidant enzyme and non-enzyme systems that capture and neutralize free radicals and LPO products. In the process of increasing fitness, the activity of antioxidant enzymes is increased and the amount of LPO products produced decreases in response to intense physical activity.
The main role in the system of antioxidant protection is played by nutritional factors – vitamin E and C, ß-carotene, reduced glutathione, selenium, which is a cofactor of the enzyme glutathione peroxidase. Increase in the consumption of vitamins of antioxidant action leads to a decrease in the formation of lipid peroxidation products, but does not completely stop it during physical activity. Under the influence of antioxidant vitamins, damage to muscle cells by products of oxidative stress is significantly reduced, muscle recovery after exercise is improved. However, an additional intake of antioxidant vitamins does not improve athletic performance compared to the normal supply of the organism with these nutritional factors.
The need for vitamins
The need for vitamins depends both on the state of the organism (internal factors) and on the influence of the environment (external factors). The need for vitamins is significantly influenced by the age of a person, the nature and intensity of work. The need for vitamins significantly increases during pregnancy and lactation, significantly increases in the North, when working in hot shops, under the ground, with strong neuropsychic stress. The same applies to persons with harmful occupations who are recommended supplementary intake of vitamins in connection with their increased consumption under the influence of harmful factors of production.
Although a decrease in physical activity and energy expenditure in old age can reduce the physiological need for vitamins, however, a violation of their absorption at this age makes it necessary to additionally take multivitamin preparations with a wide range of vitamins, including those whose lack in food of young adults is rare (vitamins B12, E, etc.).
Inadequate intake of a vitamin with food leads to its deficiency in the body and the development of a corresponding disease of vitamin deficiency, which is based on the disturbances of the biochemical, most often enzymatic, processes dependent on this vitamin.
Usually, two degrees of vitamin deficiency are distinguished: vitamin deficiency and hypovitaminosis. Aviataminosis means a state of deep deficiency of a vitamin with a detailed clinical picture of the state of its insufficiency: with a deficiency of vitamin C – scurvy, vitamin B – rickets, vitamin B1 – beriberi, vitamin PP – pellagra, vitamin B12 – pernicious anemia.
To hypovitaminosis include a state of moderate deficiency with erased nonspecific manifestations, such as loss of appetite, fatigue, irritability, and individual micro-symptoms: bleeding gums, pustular skin diseases, peeling and dry skin, brittle hair, etc. In these cases, biochemical tests, such as determining the concentration of vitamins, the activity of vitamin-dependent enzymes, already reveal a deficiency of a particular vitamin, but there is still no detailed clinical picture of its deficiency.
Along with a deficiency of one particular vitamin in practice, polyhypovitaminosis is often found in which the body lacks several vitamins. However, under these conditions, the deficiency of one of the vitamins, as a rule, is leading, and the rest – concomitant.
The main reason for hypo and avitaminosis is insufficient intake of vitamins with food. Such hypo-and avitaminosis is called primary, or exogenous.
Along with this, a deficiency of vitamins can occur with their sufficient intake of food, but due to a violation of their utilization in the body or with a sharp increase in the need for vitamins. Such hypo-and avitaminosis are called secondary, or endogenous. A special group of such conditions are congenital, genetically caused disorders of metabolism and functions of vitamins.
The intake of a number of vitamins in doses substantially exceeding the physiological requirement can lead to undesirable side effects, and in some cases to serious pathological disorders, referred to as hypervitaminosis. Particularly dangerous in this respect are the fat-soluble vitamins D and A.
The discovery of vitamins and their widespread use for preventive and curative purposes, providing the population with a sufficient amount of food led to the fact that in our country, vitamin deficiency is currently rare. Nevertheless, the problem of optimal provision of the human body with vitamins is far from its full resolution.
The most common deficiency of vitamins C (ascorbic acid), A, inadequate intake of vitamins B1, B2, folic acid and vitamin B6.
Insufficient intake of vitamins, which does not even lead to severe clinical manifestations of avitaminosis, adversely affects human health, worsens well-being, reduces efficiency, resistance to infectious agents, increases negative impact on the body of harmful conditions of work and the environment, aggravates the course of any disease, prevents them successful treatment.
Insufficient intake of ascorbic acid correlates with a higher frequency of increasing cholesterol in the blood (hypercholesterolemia) and coronary heart disease, hypertensive disease. Deficiency of vitamin A, carotenoids and some B vitamins is a factor predisposing to the development of a number of malignant tumors.
Insufficient provision of vitamins for pregnant and lactating women, whose need for these nutrients is significantly increased, causes great damage to the health of the mother and child, may be the cause of congenital malformations, hypotrophy, prematurity, and physical and mental development of children.
Prolonged insufficient intake of vitamins in childhood and adolescence adversely affects the indicators of overall physical development, endurance, prevents the formation of a healthy organism, contributes to the gradual development of metabolic disorders and chronic diseases. Finally, inadequate intake of vitamins is a factor predisposing to alcoholism and enhancing the destructive effect of alcohol on the health and psyche of a person.
Hypovitaminosis status, characteristic of a large number of healthy people, is significantly exacerbated in various diseases. Hypovitaminosis burdens the course of the underlying disease, hampers and reduces the effectiveness of therapeutic measures, complicates the outcome of surgical interventions and the course of the postoperative period. In this regard, the treatment of almost any disease should include correction of the available or possible vitamin deficiency by including multivitamin preparations in the complex therapy.
One of the important reasons for the insufficient supply of the population with vitamins is the deviation of actual nutrition from recommended norms due to local climatic and geographical peculiarities, inaccessibility of vitamin-rich foods (especially vegetables, fruits), adherence to harmful habits, habits, “fashion” diets, etc.
It is essential that the increase in the consumption of refined products and products subject to technological processing, preservation and long-term storage, which result in a significant portion of essential nutrients, results in a significant reduction in the consumption of vitamins.
The list of the most important causes of hypo-and avitaminosis
Insufficient intake of vitamins with food.
- Low content of vitamins in the diet.
- Decrease in the total amount of food consumed due to low energy expenditure.
- Loss and destruction of vitamins in the process of technological processing of food products, their storage and irrational culinary processing.
- Deviation from a balanced formula of nutrition due to national characteristics, religious prohibitions and perversions.
- Anorexia (loss of appetite).
- The presence of vitamins in some products is difficult to recycle.
Inhibition of intestinal microflora, which produces vitamins.
- Diseases of the gastrointestinal tract.
- Consequences of chemotherapy (syndrome of excessive bacterial growth).
Violations of vitamin assimilation.
- Violation of absorption of vitamins in the gastrointestinal tract with diseases of the stomach, intestines, lesions of the hepatobiliary system, as well as in old age (in particular, the violation of the secretion of bile, necessary for absorption of fat-soluble vitamins).
- Utilization or cleavage of vitamins supplied with food by intestinal parasites and pathogenic intestinal microflora – avitaminosis B12 during invasion with a wide ribbon, cleavage of vitamin B1 by thiaminase microflora inhabiting the intestines of freshwater fish.
- Violation of the exchange of vitamins and the formation of their biologically active (coenzyme) forms for various diseases, the effects of toxic and infectious agents, chemotherapy and the use of a number of medications.