Vitamin A norm per day. Vitamin A: benefits, symptoms of deficiency, contraindications and signs of overdose - video

In the process of consuming vitamin A, the daily intake of which plays an important role, it is important to strictly adhere to a special regimen. It is selected individually for each patient by the attending physician. As a result, after taking such a medicinal course, a person’s well-being significantly improves, and all body systems begin to work with new strength. It is important not to overdo it in this matter. And then the vitamins will be extremely beneficial.

What is vitamin A for?

The first thing vitamin A is vital for is the immune system, the work of which this component significantly stimulates. As a result, the body's resistance to all kinds of infections increases, and the wound healing process accelerates.

Moreover, the correct dosage of vitamin A affects the following systems:

Vision. Vitamin A takes part in the production of rhodopsin, one of the visual pigments used to provide normal vision at night and quick recovery eye cells.
Bone formation and growth. Vitamin A - essential component, ensuring the growth of healthy and strong bones. In addition, this component has a beneficial effect on the formation of teeth. This is why retinol is most often prescribed to children.
Nervous system. It is vitamin A that is responsible for the formation of membranes and myelin, from which the sheath of nerve fibers is formed.
Hormonal background. Retinol supports the correct functioning of the adrenal glands and promotes the production of thyroid hormones.
Leather. To maintain youthful and beautiful skin, vitamin A can be used as a component for making masks or taken orally. The result of this procedure will be obvious: the skin will become smooth and clear of fine wrinkles.

Taking retinol will also be relevant for pregnant women, whose body often experiences a serious deficiency of vitamins and useful microelements. Thanks to component A, the full development of the embryo is ensured, and in the mother’s body after childbirth, milk production is observed, which contains a high percentage of vitamins.

Of course, it is not possible for the average person to independently determine what the daily dose of a vitamin should be. However, a deficiency of this component can be easily noticed by the condition of hair and nails, which become dull and brittle.

Some patients also note a deterioration in the condition of the skin, on which acne and numerous small rashes. Deal with them with the help of privates cosmetic preparations not possible. That is why a person who notices negative changes in his own body should immediately consult a doctor.

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How to get vitamin A?

Typically, a person's daily requirement for vitamins can be obtained in two forms. The first is retinol in pure form, and the second is a carotenoid, converted to provitamin A as a result of the metabolic process.

Retinol itself is usually found in products of animal origin: liver, caviar, butter, cheeses, milk and fish oil.

By eating at least one of them every day, you can easily satisfy daily requirement vitamin A. At the same time, it is strictly not recommended to abuse these products. After about a month of active use, you should take at least a short break.

It would be useful to take a blood test before and after such a diet. It is he who will be able to unambiguously determine whether it is worth sticking to a similar diet in the future or whether the vitamin requirement has already been fully met.

For people who have an urgent need to increase the level of beta-carotene in their body, a variety of vegetable diets, which contain carrots, bell pepper, pumpkin, parsley, rose hips, tomatoes and lettuce. However, the use of such components must be wisely combined with meat and fish products, which must be present in the diet at least once a day.

Vitamin C is necessary element, which takes part in many processes in the body. If it is deficient, there may be serious problems at work internal organs And various systems. It is important to know the daily intake of vitamin C, since an excess of this substance is unfavorable for health. There are many foods that can be included in your diet to nourish your body.

About beneficial properties ascorbic acid One can talk endlessly, but one can still identify such functions. Firstly, this substance helps strengthen the immune system and collagen synthesis. Secondly, vitamin C has antioxidant properties and is also important for the production of hormones. Thirdly, this substance strengthens cardiovascular system and preserves the cells of the nervous system.

Daily intake of vitamin C

Scientists have conducted a considerable number of experiments that have made many useful discoveries. For example, it was possible to establish that what older person, the more ascorbic acid he needs. To determine required quantity vitamin C, it is important to take into account age, gender, lifestyle, bad habits and other characteristics.

Daily intake of vitamins C depending on some indicators:

For men. The recommended daily dose is 60-100 mg. At insufficient quantities ascorbic acid, sperm density decreases in men.
For women. The daily requirement of vitamin C in this case is 60-80 mg. If this is lacking useful substance you feel weak, problems with hair, nails and skin arise. It is worth noting that if a woman takes oral contraceptives, then the specified amount should be increased.
For children. Depending on age and gender, the norm of vitamin C per day for children is 30-70 mg. Ascorbic acid is needed for the child’s body for the restoration and growth of bones, as well as for blood vessels and immunity.
For a cold. As a preventive measure, as well as for the treatment of colds and viral diseases, it is worth increasing the indicated dose to 200 mg. If a person suffers from bad habits, then the amount should be increased to 500 mg. Thanks to the increased intake of ascorbic acid, the body fights viruses faster and more effectively, which means recovery occurs faster.
During pregnancy. A pregnant woman should consume more ascorbic acid than usual, since this substance is necessary for correct formation the fetus, and for the immunity itself expectant mother. Minimum quantity for pregnant women is 85 mg.
When playing sports. If a person is actively involved in sports, then he needs to get more vitamin C from 100 to 500 mg. Ascorbic acid is important for ligaments, tendons, bones and muscles. In addition, this substance is necessary for the complete absorption of protein.

If the vitamin C requirement cannot be achieved through consumption necessary products nutrition, then a person is recommended to drink special multivitamin preparations. In extreme cold and heat, the body should receive more ascorbic acid than usual, by about 20-30%. If a person is sick, he experiences frequent stress or suffers from bad habits, then you should add 35 mg to the daily norm. It is important to say that the required amount of acid should be divided into several doses, which means they will be absorbed evenly.

One of the very first vitamins that scientists managed to discover is vitamin A. Retinol, dehydroretinol, antixerophthalmic or anti-infective vitamin are other names for this substance. It represents fat-soluble vitamin, therefore does not dissolve in water. Do not forget that retinol in large quantities toxic, its excess can lead to negative consequences for human health. From our article you will learn what vitamin A is, what properties it has and how much retinol you need to consume per day to satisfy the body's daily needs.

Let's study in more detail the question of what vitamin A is and what features it has. For its absorption, fats, proteins and minerals are necessary, since it does not dissolve in water. But during heat treatment or during long exposure to air, 20 to 40% of the retinol in products is destroyed.

Retinol has unique property- it can accumulate in the liver “for a rainy day.” Therefore, it does not require daily replenishment; it is recommended to use it as much as possible in the summer more products with vitamin A, since they are most abundant during this season.

In total, there are 2 forms of this substance: retinol in finished form(found in products of animal origin) and provitamin A (carotene). Once in the human body, it is converted into the vitamin itself as a result of oxidative cleavage. The second form of the anti-infective vitamin is found in most cases in plant foods.

Benefits of Vitamin A

Retinol does important function in many biological processes human body. Let's take a closer look beneficial properties vitamin A;

Promotes normalization metabolic processes, regulates protein synthesis;
Necessary for the formation of bones, hair, gums, teeth;
Ensures optimal performance visual analyzer, taking active participation in the synthesis of visual retinal pigment;
Retinol is responsible for the beautiful, even color of the nail plate, so it is mandatory component diets for nails;
In a positive way affects the body's immune system, helping to cope with various infections;
Slows down the aging process;
Used to treat skin diseases (acne, psoriasis), helps with burns and wounds;
Helps prevent and cause cancer diseases;
Vitamin A is an excellent antioxidant;
Serves as a good prevention of heart disease. Reduces the accumulation of cholesterol on the walls of blood vessels;
People suffering from a disease such as AIDS can live longer by regularly using retinol;
Regulates blood sugar ratio.

In addition, the effect of taking retinol has a positive effect on youth, elasticity and beauty of the skin. It restores tissue in all its layers, so it is actively used in modern medicine and cosmetology. As you can see, vitamin A is used to preserve internal and external health our body.

Retinol for athletes

Vitamin A is of great benefit to athletes and people whose lives are connected with large physical activity. It helps normalize protein synthesis, which is especially important for increasing muscle mass. It is also necessary for the accumulation of glycogen, the main energy store in the human body.

With sports diets, a lack of retinol may occur. Therefore, you need to include liver, dairy products and vegetables in your diet. During active sports training, it is necessary to increase daily dose retinol, in order to prevent its insufficient intake in the body in the future.

Vitamin A deficiency

A lack of retinol is dangerous because various skin diseases, peeling, early aging skin. The body becomes susceptible to various infectious diseases. Insomnia appears and poor appetite, hair falls out a lot, the genitourinary system suffers.

The most common sign of a lack of retinol in the body is the appearance of “ night blindness" Vision is impaired in the dark, the mucous membrane dries out, and conjunctivitis of the eyes may begin.

Vitamin A deficiency during pregnancy is dangerous birth defects fetal development and spontaneous miscarriages.

Symptoms of vitamin A deficiency manifest themselves in dry skin (especially in the elbows and knees), the appearance of acne, pustules, dandruff, and deterioration in the condition of hair and nails. Other signs of retinol deficiency are frequent infectious diseases, malfunctions immune system, weakened vision and erection in men.

Excess vitamin A: symptoms and consequences

At unbalanced diet Many people try to meet their retinol needs with modern drugs. They don’t think at all that this can lead to excessive intake of the vitamin into the body and further intoxication.

An overdose of retinol is dangerous because the vitamin accumulates in the human body in large quantities, causing disruption of the functioning of many organs and leading to cirrhosis of the liver.

The main signs of an overdose of vitamin A: an increase in the size of the liver and spleen, drowsiness, diarrhea, intestinal upset, nervous condition, depression, disorder menstrual cycle in women, joint pain, high blood pressure, nausea, bleeding gums.

Daily intake of vitamin A

To determine the optimal daily norm retinol for adults and children there are a number of things to consider individual characteristics person: gender, age, availability sports training, diseases, etc.

The daily intake of vitamin A for men is approximately 710-1010 mcg per day, the daily intake of retinol for women is 600-810 mcg.

Children under 3 years of age should consume no more than 400 mcg of retinol daily; from 3 to 10 years of age, the norm is 450-700 mcg. In adolescents, the daily requirement for vitamin A is 700-1000 mcg.

The daily requirement of vitamin A for lactating and pregnant women, as well as for athletes, is slightly higher - approximately 1000-1400 mcg. However, increasing the daily dosage of retinol is possible only after consultation with your doctor.

Compatibility of retinol with other substances

Zinc can also be considered a beneficial “partner” of vitamin A. It is needed to convert beta-carotene into retinol.

Vitamin A should not be taken together with alcohol and alcohol-containing drugs (leads to liver damage), retinoids, hyperlipidemic drugs, as well as mineral laxatives.

G-Lactone 2,3-dehydro-L-gulonic acid.

Description

Vitamin C is a water-soluble vitamin. First isolated in 1923-1927. Zilva (S.S. Zilva) from lemon juice.

According to the results of numerous scientific research ascorbic acid is involved in the regulation of redox processes, carbohydrate metabolism, blood clotting, tissue regeneration, in the synthesis steroid hormones, collagen; increases the body's resistance, reduces vascular permeability, which is important for various capillary bleedings, infectious diseases, nasal, uterine and other bleeding. Helps maintain healthy condition skin, participates in immune reactions, improves iron absorption. Has antioxidant properties.

Playing important role in the functioning of the immune system, helping to increase the body's resistance to viral and bacterial infections.

For diseases accompanied by fever, as well as increased physical and mental stress The body's need for vitamin C increases.

Vitamin C is one of the body's defense factors against the effects of stress. Strengthens reparative processes. There are theoretical and experimental prerequisites for the use of vitamin C to reduce the risk of developing cancer.

Sources of ascorbic acid

A significant amount of ascorbic acid is found in foods plant origin(citrus fruits, leafy green vegetables, melon, broccoli, Brussels sprouts, cauliflower and cabbage, black currants, bell peppers, strawberries, tomatoes, apples, apricots, peaches, persimmons, sea buckthorn, rose hips, rowan, baked jacket potatoes) . It is present insignificantly in products of animal origin (liver, adrenal glands, kidneys).

Herbs rich in vitamin C: alfalfa, mullein, burdock root, chickweed, eyebright, fennel seed, fenugreek, hops, horsetail, kelp, peppermint, nettle, oats, cayenne pepper, red pepper, parsley, pine needles, yarrow, plantain , raspberry leaf, red clover, skullcap, violet leaves, sorrel.

		Name of food products	Amount of ascorbic acid
Vegetables		Fruits and berries		Eggplant	5	Apricots	10	Canned green peas	10	Oranges	50	Fresh green peas	25	Watermelon	7	Zucchini	10	Bananas	10	White cabbage	40	Cowberry	15	Sauerkraut	20	Grape	4	Cauliflower	75	Cherry	15	Potatoes are stale	10	Pomegranate	5	Freshly picked potatoes	25	Pear	8	Green onion	27	Melon	20	Carrot	8	Garden strawberries	60	cucumbers	15	Cranberry	15	Sweet green pepper	125	Gooseberry	40	Red pepper	250	Lemons	50	Radish	50	Raspberry	25	Radish	20	Tangerines	30	Turnip	20	Peaches	10	Salad	15	Plum	8	Tomato juice	15	Red currant	40	Tomato paste	25	Black currant	250	Red tomatoes	35	Blueberry	5	Horseradish	110-200	Dried rosehip	Up to 1500	Garlic	Traces	Apples, Antonovka	30	Spinach	30	Northern apples	20	Sorrel	60	Southern apples	5-10	Dairy products				Kumis	20	Mare's milk	25	Goat milk	3	Cow's milk	2

Remember that few people, and especially children, eat enough fruits and vegetables, which are the main food sources vitamin. Cooking and storage lead to the destruction of a significant part of vitamin C. In states of stress, exposure unfavorable factors environment(smoking, industrial carcinogens, smog) vitamin C is consumed faster in tissues.

To prevent hypovitaminosis, rose hips are often used. Rose hips differ relatively high content ascorbic acid (not less than 0.2%) and are widely used as a source of vitamin C. Fruits collected during the ripening period and dried are used different types rosehip bushes. They contain, in addition to vitamin C, vitamins A, E, sugars, organic acids, dietary fiber. Used in the form of infusion, extracts, syrups.

An infusion of rose hips is prepared as follows: 10 g (1 tablespoon) of fruits are placed in an enamel bowl, pour 200 ml (1 glass) of hot boiled water, close the lid and heat in a water bath (in boiling water) for 15 minutes, then cool at room temperature for at least 45 minutes, filter. The remaining raw materials are squeezed out and the volume of the resulting infusion is adjusted boiled water up to 200 ml. Take 1/2 cup 2 times a day after meals. Children are given 1/3 glass per dose. To improve the taste, you can add sugar or fruit syrup to the infusion.

Daily requirement for ascorbic acid

A person’s daily need for vitamin C depends on a number of reasons: age, gender, work performed, physiological state body (pregnancy, breastfeeding, presence of disease), climatic conditions, presence of bad habits.

Illness, stress, fever and exposure toxic substances (cigarette smoke, chemicals) increase the need for vitamin C.

In hot climates and in the Far North, the need for vitamin C increases by 30-50 percent. A young body absorbs vitamin C better than an older one, so in older people the need for vitamin C is slightly increased.

It has been proven that contraception(oral contraceptives) lower the level of vitamin C in the blood and increase the daily requirement for it.

The weighted average physiological requirement for the vitamin is 60-100 mg per day.

Table. Norms of physiological requirement for vitamin C [MP 2.3.1.2432-08]

The body quickly uses up incoming vitamin C. It is advisable to constantly maintain a sufficient supply of vitamin C.

Signs of hypervitaminosis

Vitamin C is generally well tolerated in doses up to 1000 mg/day.

If taken in too large doses, diarrhea may develop.

Large doses can cause hemolysis (destruction of red blood cells) in people suffering from a lack of the specific enzyme glucose-6-phosphate dehydrogenase. Therefore, people with this disorder can take increased doses of vitamin C only under the strict supervision of a doctor.

When using large doses of ascorbic acid, pancreatic function may be impaired with impaired insulin synthesis.

Vitamin C promotes the absorption of iron in the intestines.

Gummies and chewing gum with vitamin C can damage tooth enamel, so you should rinse your mouth or brush your teeth after taking them.

Large doses should not be taken by people with increased coagulability blood, thrombophlebitis and a tendency to thrombosis, as well as diabetes mellitus. At long-term use large doses of ascorbic acid may inhibit the function of the insular apparatus of the pancreas. During treatment, it is necessary to regularly monitor its functional ability. Due to the stimulating effect of ascorbic acid on the formation of corticosteroid hormones during treatment large doses it is necessary to monitor kidney function, blood pressure and the level of hormones in the blood.

Extremely permissible level vitamin C intake for adults is 2000 mg/day ( Methodical recommendations"Norms physiological needs in energy and nutrients For various groups population Russian Federation", МР 2.3.1.2432-08)

Symptoms of hypovitaminosis

According to the head of the laboratory of vitamins and minerals Institute of Nutrition of the Russian Academy of Medical Sciences prof. V.B. Spiricheva, results of examinations in different regions Russia, show that the vast majority of preschool and school age lacks what they need normal height and development of vitamins.

The situation is especially unfavorable with vitamin C, the deficiency of which was identified in 80-90% of the children examined.

When examining children in hospitals in Moscow, Yekaterinburg, Nizhny Novgorod and other cities, vitamin C deficiency is found in 60-70%.

The depth of this deficiency increases in the winter-spring period, however, in many children, insufficient supply of vitamins persists even in the more favorable summer and autumn months, that is, it is year-round.

But insufficient intake of vitamins significantly reduces the activity of the immune system, increases the frequency and severity of respiratory and gastrointestinal diseases. According to domestic researchers, a lack of ascorbic acid in schoolchildren halves the ability of leukocytes to destroy pathogenic microbes that have entered the body, resulting in the frequency of acute respiratory diseases increases by 26-40%, and vice versa, taking vitamins significantly reduces the incidence of acute respiratory infections.

Deficiency can be exogenous (due to low content ascorbic acid in food products) and endogenous (due to impaired absorption and digestibility of vitamin C in the human body).

If there is insufficient vitamin intake over a long period of time, hypovitaminosis may develop. Possible signs Vitamin C deficiency:

bleeding gums
cyanosis of lips, nose, ears, nails, gums
swelling of the interdental papillae
ease of bruising
poor healing wounds
lethargy
hair loss
pale and dry skin
irritability
joint pain
feeling of discomfort
hypothermia
general weakness

Preservation of vitamin C during cooking

Name of dishes	Preservation of vitamin compared to the original raw material in%
Boiled cabbage with broth (cooking 1 hour)	50	Cabbage soup standing on a hot plate at 70-75° for 3 hours	20	Same with acidification	50	Cabbage soup standing on a hot plate at 70-75° for 6 hours	10	Cabbage soup from sauerkraut(cooking 1 hour)	50	Stewed cabbage	15	Potatoes, fried raw, finely chopped	35	Potatoes boiled for 25-30 minutes in their skins	75	Same, cleaned	60	Peeled potatoes, kept in water at room temperature for 24 hours	80	Mashed potatoes	20	Potato soup	50	The same, standing on a hot stove at 70-75° for 3 hours	30	Same thing, standing for 6 hours	traces	Boiled carrots	40

From the book by O.P. Molchanova "Fundamentals" rational nutrition", Medgiz, 1949.

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When studying the effect of vitamin C on passive smokers, it was found that people staying in smoky rooms experience oxidative stress, which accelerates the progression of atherosclerosis.

Conclusion: passive smokers need vitamin C supplements.

* dietary supplement. NOT A MEDICINE

Vitamin A is important for maintaining visual acuity and health skin, strength and beauty of hair. It is necessary to strengthen the immune system, preserve normal condition bone and dental tissues, slowing down the aging process, preventing the appearance of malignant cells. For women, men and children installed daily norm vitamin consumption. In certain cases daily dosage rises.

Vitamin A, also called retinol, is a fat-soluble compound. It is normally absorbed in the body if there is sufficient fat and some minerals in the food consumed. Retinol tends to accumulate in the body, so it is not necessary to use it daily.

The vitamin is necessary to prevent heart pathologies, normalize the functioning of women and men reproductive system, improving the functions of sex hormones. The substance also fights viral infection, strengthens the structure of hair and nail plates, accelerates wound healing.

Daily dose for people of different ages and gender

The daily dose of the vitamin is different for women, men, children and breastfeeding mothers.

	norm per day, mg	norm per day, IU	maximum dose per day, mg
baby up to 6 months
infant from 6 to 12 months
child from one to 3 years old
child from 3 to 8 years old
boy from 8 to 14 years old
youth from 14 to 18 years old
man over 18 years old
girl from 8 to 14 years old
girl from 14 to 18 years old
woman over 18 years old
pregnant under 19 years old
pregnant after 19 years
breastfeeding mother under 19 years old
breastfeeding mother after 19 years

Information about units of measurement

IU is an international unit of dose measurement, depending on biological activity substances. Used in setting doses of vitamins, medicinal substances, hormones and other active compounds. For different substances the amount corresponding to 1 IU is not the same.

Thus, the following indicators have been established for vitamin A:

1 IU retinol = 0.3 mcg (0.0003 mg);
1 IU beta carotene = 0.6 mcg (0.0006 mg).

It turns out that the optimal daily dose of retinol is 1 mg or approximately 3300 IU, and its predecessor beta-carotene is 6 mg or 10,000 IU. These are averages that do not take into account a person’s gender and age.

When is the need for vitamin A increased?

those engaged in heavy physical labor;
constantly facing stress;
having chronic diseases;
frequently undergoing x-rays;
taking medications to lower blood cholesterol;
often working at a computer, which strains the eyes;
alcohol abusers.

The need for vitamin A is increased in athletes following a high-protein diet, as retinol accelerates the absorption of proteins. Vitamin in increased doses is important for actively growing and developing child from 3 to 12 years old, as well as for schoolchildren experiencing high intellectual stress.

Sources of Vitamin A

From plant sources vitamin can be noted:

legumes;
carrots, pumpkin and other orange and yellow vegetables;
sea buckthorn;
melon and watermelon;
apricots;
apples;
grape;
sorrel, parsley, spinach, mint and other herbs.

Rich animal sources of retinol include:

beef liver;
caviar;
fish oil;
egg yolk;
milk and dairy products.

Symptoms of Vitamin A Deficiency

The main reason for the lack of vitamin in the body is poor nutrition, which includes few fats and nutrients.

The development of hypovitaminosis A can be guessed by the following signs:

rapid formation of wrinkles;
the appearance of dandruff;
increased sensitivity to pain and temperature influences;
tearing in the wind and cold;
disruption of the urinary system;
weakening erectile function, acceleration of ejaculation;
rapid deterioration of vision.

Vitamin A deficiency causes negative changes in almost all organs and systems. With hypovitaminosis, pathologies are observed digestive tract, infectious lesion intestines, acceleration of the aging process, the formation of malignant cells, weakened immunity, anemia, deterioration in appearance, sleep disturbance.

In a child, a lack of vitamin can cause blindness. Children suffering from hypovitaminosis A often contract a viral infection.

Vitamin A overdose

If you consume too much of the vitamin, the following symptoms are observed:

drying out of the skin;
headaches;
nausea;
disturbance of emotional state;
bleeding gums;
diarrhea;
defects in the development of the embryo in the womb;
miscarriage.

IN medical practice There have been cases where a person died from a severe overdose of retinol. Overdose is especially dangerous for pregnant women. In the mother it can cause osteoporosis and other serious pathologies, and the fetus developing in the womb has severe developmental defects. Therefore, expectant mothers need to take exactly as much vitamin A per day as prescribed by the doctor.