In the absence of vitamin A it develops. Eyes and vision
- This condition is caused by a long-term insufficient supply of vitamin A to the body from food, especially if rice is the main food product (does not contain carotene).
- Vitamin A deficiency occurs when there is not enough protein in the diet (marasmus or kwashiorkor), mainly due to food deficiency (but the storage and transport of vitamin A is also impaired).
Secondary vitamin A deficiency
- This condition occurs when there is a problem converting carotene to vitamin A or when the absorption, storage, or transport of vitamin A is decreased.
- Occurs in celiac disease, tropical sprue, giardiasis, cystic fibrosis, other diseases of the pancreas, cirrhosis, bypass surgery duodenum and obstruction of the bile ducts.
Epidemiology
The following segments of the population are most susceptible to vitamin A deficiency:
- Vitamin A deficiency is rare in developed countries but is extremely common in developing countries, especially in sub-Saharan Africa and South Asia.
- Globally, vitamin A deficiency affects 100–140 million children, of whom 4.4 million have xerophthalmia.
- Recent immigrants or refugees from developing countries.
- Toddlers and children preschool age living below the poverty line.
- In pregnant women, vitamin A deficiency occurs especially in the last trimester (the need of the fetus and mother for vitamin A during this period is the highest). Read more - Vitamin A during pregnancy: dosage, effect on the fetus, norm.
Other risk factors for vitamin A deficiency:
- Fat malabsorption, cholestasis, inflammatory disease bowel disease (IBD), cystic fibrosis (cystic fibrosis), pancreatic insufficiency or after small bowel transplant surgery.
- Vegan diet.
- Alcoholism.
Symptoms of Vitamin A Deficiency
Mild forms of vitamin A deficiency may not cause any symptoms. However, there may still be an increased risk of developing respiratory infections and gastroenteritis, as well as delayed growth and bone development. There is also a risk of infertility secondary to impaired spermatogenesis and an increased risk of miscarriage.
Eyes and vision
Pathognomonic changes occur in the eye (usually bilateral, although they can be of varying degrees):
- Poor adaptation to darkness - night blindness.
- Keratomalacia (thinning and ultimately ulceration of the cornea - liquefaction necrosis).
- Dry conjunctiva, dry cornea, xerophthalmia.
- Bitot's spots (areas of abnormal squamous proliferation and keratinization of the conjunctiva, causing oval and triangular foamy spots at the periphery of the white of the eye).
- Corneal perforation.
- Blindness due to structural damage to the retina.
- Decreased vitamin A concentration increases the risk of blindness in children, infected with the virus measles
Changes in the eye
Early symptoms begin with itching, burning and inflammation of the eyelids, followed by various diseases eye.
Long-term vitamin A deficiency results in a condition known as nyctalopia or blindness, in which a person is unable to see well in dim light, especially after exposure to bright light. The "blindness" is due to the fact that vitamin A combines with a protein in the retina of the eye to form a pigment called rhodopsin (visual purple). Rhodopsin is formed by a combination of vitamin A aldehyde (retinone) and protein (opsin). It bleaches under strong light. During the photochemical reaction, some vitamin A is lost. If there is enough vitamin A, the eyes quickly adapt to dim light and you can see almost immediately.
Night blindness is more common among poor people. Men suffer more than women. A pregnant woman often suffers from night blindness, partly due to underlying medical conditions and partly due to increased need in vitamin A during this period. Night blindness sometimes occurs due to a physical defect in the eyes or in other cases. This condition associated with vitamin A deficiency is called Functional Night Blindness.
Xerophthalmia
This condition occurs when vitamin A deficiency is severe and long-lasting. Xerophthalmia occurs due to changes in epithelial tissues eyes. The cornea becomes dry, wrinkled, dull, cloudy and pigmented. The tear glands stop producing tears that normally moisturize the eye, washing away bacteria and other foreign particles - leading to dryness and inflammation. eyelids, and loss of eye shine. Inflammation leads to ulceration. The final stage is keratomalacia - softening and destruction eyeball leading to blindness.
Xerophthalmia is sometimes associated with Bitot's spots, which are well-demarcated foamy white or grayish irregular areas present on the periphery of the cornea of the eye. These spots do not interfere with vision. Keratomalacia usually affects children between 1 and 5 years of age due to a lack of vitamin A in their diet.
Epithelial changes
Vitamin A deficiency leads to atrophy (degeneration) and keratinization (hardening) of the epithelium. Epithelial cells flatten and accumulate on top of each other. This increases susceptibility to serious infection not only of the eyes, but also of the nasal passages, sinuses, middle ear, pharynx, mouth, respiratory tract, lungs and genitourinary tract. The epithelium of the eye is so severely damaged that the condition is incurable.
Skin and hair
A person experiencing a lack of vitamin A in the body may also experience following symptoms related to skin and hair:
- Dry skin, dry hair, itching.
- Follicular hyperkeratosis secondary to blockage hair follicles, with keratin plugs.
Vitamin A deficiency can lead to xeroderma (dry, scaly, itchy skin) and follicular hyperkeratosis (dry, rough, scaly skin). There is a thickening of the keratin layers of the skin on the palms and soles. Follicles like goose pimples, appear first on upper parts arms and hips, then on the shoulders, back and buttocks. This condition is called phrynoderma or "toad skin." Sweat glands The skin is blocked by horny keratin plugs, and therefore their secretion decreases.
Respiratory system
The mucous membranes of the respiratory organs, such as the nose, throat, trachea and bronchi, become dry and rough. Thus, Airways are exposed increased risk development of bacterial infection.
Digestive system
Due to vitamin A deficiency digestive tract dries out, which leads to a decrease in the secretion of digestive juices, lack of absorption and increased susceptibility to intestinal infection and diarrhea.
Reproductive system
Keratinizing metaplasia occurs in renal pelvis, bladder, uterus, oviduct and accessory sex glands. Vaginitis can be observed in women.
Urolithiasis disease
This is a disease in which urinary calculi (stones) consisting of calcium phosphate are present. Due to a lack of vitamin A, keratinization of the epithelium of the urogenital tract occurs, which is later accompanied by bacterial invasion.
Changes in the skeletal system
Lack of vitamin A leads to uneven development of the skeleton, including the skull and spinal column. This leads to distortion and damage to the brain and spinal cord. Bone and tooth growth is noticeably weakened.
Reduced resistance to infection
Vitamin A is necessary for the maintenance and functioning of the body's mucous membranes. When there is a deficiency, the membranes become thin, dry, porous and scaly. They can't fulfill their protective functions, and bacteria have free access. Thus, vitamin A deficiency reduces barrier functions against certain infections.
Treatment of vitamin A deficiency
Treatment for subclinical vitamin A deficiency includes consuming vitamin A-rich foods such as liver, beef, chicken, eggs, fortified milk, carrots, mangoes, sweet potatoes (yams), and leafy green vegetables.
Good animal sources of vitamin A are:
- liver
- egg yolks
- whole milk
- butter
- whole small fish (with liver intact)
Animal sources of vitamin A, including milk, are more bioavailable than plant sources, such as carrots and other orange-yellow fruits and vegetables, and dark green leafy vegetables.
You can see a list of foods rich in vitamin A on this page - 20 foods rich in vitamin A: list of foods with vitamin A.
Medicines
For clinically obvious vitamin A deficiency, treatment is limited to daily oral administration vitamin A supplements.
Vitamin A overdose can cause symptoms and signs such as:
- roughening of the skin
- dry hair
- liver enlargement
- increased erythrocyte sedimentation rate, increased calcium concentration and alkaline phosphatase in serum
Taking into account the data indicating that high levels vitamin A may cause birth defects Pregnant women and women who may become pregnant are not recommended to take vitamin A supplements (including fish oil supplements). They are also not recommended to consume liver or foods such as liver paste or liver sausage, except when indicated by a doctor.
Forecast
If a patient asks for medical care When the deficiency is subclinical, the prognosis is good. As blindness progresses, the prognosis worsens. Irreversible conditions include punctate keratopathy, keratomalacia, and corneal perforation.
- For patients with early mild eye problems fast treatment may result in complete preservation of vision without residual impairment (completely restored within a few weeks).
- In developing countries, severe vitamin A deficiency, often caused by significant malnutrition, leads to death in most cases. The mortality rate in children with severe vitamin A deficiency is up to 50%.
- Only about 40% of patients with corneal xerophthalmia continue to see a year later (25% are completely blind and the rest are partially blind).
Prevention
Liver, beef, chicken, eggs, whole milk, fortified milk, carrots, mangoes, orange fruits, sweet potatoes, spinach, kale and other green vegetables are among the foods rich in vitamin A.
It is recommended to eat at least five servings of fruits and vegetables per day to ensure a normal intake of carotenoids in the body. A variety of foods, such as breakfast cereals, baked goods, breads, crackers, and cereal bars, are often fortified with vitamin A.
People at increased risk of vitamin A deficiency should take vitamin A supplements to reduce morbidity, mortality, and the risk of blindness in children early age aged from 6 months to 5 years.
Due to a lack of vitamin A in the body, negative changes can occur - blurred vision, conjunctivitis, xerophthalmia, skin hyperkeratosis. In addition, people suffering from a deficiency of this vitamin are prone to intestinal and respiratory diseases. Let's figure out together why this happens.
Importance of Vitamin A
Vitamin A plays important role in the human body:
- takes part in cell growth processes;
- supports color vision;
- participates in the metabolism of organic compounds;
- participates in the synthesis of sex hormones;
- supports protective forces body;
- protects against exposure free radicals.
Vitamin A is a fat-soluble substance that consists of a number of compounds with similar structures: retinol, dehydroretinol, retinal, retinolic acid, esters and their spatial isomers.
Retinol helps maintain stable blood sugar levels. Therefore, it is believed that vitamin A is especially important in the treatment of hypertension, diabetes mellitus and obesity.
Causes of hypovitaminosis A
Vitamin A deficiency can be caused by impaired absorption in the intestines. This usually occurs with chronic diseases of the intestines, liver, pancreas, celiac disease, and iron deficiency anemia. Eating even a small amount of fat can reduce the absorption of vitamin A. In addition, low protein intake can also reduce vitamin A levels.
The cause of hypovitaminosis can be a significant loss of it by the body due to cancer, diseases urinary tract and chronic infectious diseases.
At birth, the baby's vitamin A level is reduced. But it rises quickly, since the main food product of a newborn (breast milk) is rich in this vitamin. Therefore, with a healthy appetite, the baby is protected from hypovitaminosis. However, if after switching to adult food The child’s diet will contain a small amount of foods rich in vitamin A, this will affect his health. The age of 2 to 3 years is especially dangerous. To prevent this from happening, the baby needs to eat more vegetables, fruits, dairy products, liver, and take vitamin supplements.
Signs of deficiency
Hypovitaminosis manifests itself in different ways. Its main symptom is loss twilight vision. Other symptoms may soon appear. Processes of keratinization skin and mucous membranes (mainly in the oral cavity) are disrupted.
Dry skin in teenagers before puberty may be a sign of retinol deficiency. In this case, it becomes keratinized and peels.
In adults, hypovitaminosis can cause:
- hair loss, dandruff;
- brittle nails;
- increased keratinization of the skin;
- premature aging of the skin, formation of wrinkles;
- lacrimation in the cold;
- redness of the eyelids, mucus formation in the corners of the eyes;
- erectile dysfunction.
Retinol deficiency contributes to the development of dermatological diseases, hypersensitivity tooth enamel, diseases digestive systems s ( atrophic gastritis), liver cysts, pancreatic cancer, gynecological pathologies(mastopathy, breast tumors). In addition, a deficiency of this substance can cause frequent colds and chronic diseases upper respiratory tract, slow growth and development (in children).
The main problem with vitamin A deficiency is that it impairs the functioning of immune system and the body becomes vulnerable to various types of infections.
Carnitine deficiency causes the development of muscle necrosis. Characteristic signs of this disease: muscle pain, weakness, general malaise. Vitamin A deficiency is very dangerous and requires treatment.
Treatment
Retinol deficiency in the human body is corrected using medical supplies. To do this, the doctor makes an appointment synthetic products containing large amounts of vitamin A.
Retinol
An effective remedy for hypovitaminosis A. It comes in capsules or liquid form (for external use). The drug must be taken as prescribed by your doctor. You need to follow this rule, even if your goal is prevention. Required dose determined depending on age, as well as individual characteristics body. At lung disorders or medium degree daily dosage Retinol for an adult is 33,000 IU, for a child – 5,000 IU. For prevention, they usually consume 3300 IU per day (for an adult).
During pregnancy, the use of Retinol should be treated with extreme caution. Excessive amounts of this drug can lead to irreparable problems in the development of the baby. You should also remember about the dangers of Retinol when planning to conceive a child. Active ingredient of this drug accumulates in the body.
Tocopherol
Used in cases where deficiency of vitamins A and E occurs simultaneously. K popular means containing both of these vitamins is Aevit.
The course of treatment usually takes several weeks. But in severe cases, one course of therapy may not be enough and additional or repeated treatment will be required.
Vitamin A (retinol) plays a primary role in maintaining general health humans, in particular in maintaining the functioning of the immune, reproductive systems, the organ of vision and the integrity of epithelial tissues. Lack of it organic compound can negatively affect primarily visual acuity and skin condition. If the doctor suspects a lack of retinol in the body, he prescribes a determination of its concentration in venous blood. The test can be taken by referral or independently (for preventive purposes). It is also important to examine the gastrointestinal tract: hypovitaminosis can develop due to a decrease in the quality of absorption of vitamin A in the small intestine.
How to suspect a lack of retinol?
Vitamin A deficiency causes the following symptoms:
- visual disturbances, especially at dusk;
- dry skin;
- damage to mucous membranes;
- increased fragility of nails and hair;
- physical weakness, decreased performance;
- peeling of the skin;
- increased sensitivity of the cornea, formation of ulcerative defects on the eye mucosa;
- dizziness;
- tendency to develop urolithiasis;
- decreased activity of the immune system, tendency to develop infectious and inflammatory diseases.
In children, hypovitaminosis A can even lead to a delay in physical and mental development, severe weakness, decreased twilight vision. If you notice even a few symptoms of retinol deficiency, you should consult a doctor. The specialist will conduct an examination and diagnose accurate diagnosis, and, if necessary, prescribe treatment for the disease and adherence to a certain diet.
Experience world scientists showed that when retinol reserves are depleted, people experience serious problems with the immune system, skin, and reproductive system. Even banal acute respiratory viral infections can lead to severe bronchopulmonary complications and death from associated infections.
If hypovitaminosis A develops, the epithelium suffers internal organs. This causes keratinization of the respiratory tract mucosa, genitourinary organs, intestines, organ of vision. Secretion epithelial cells bronchi, lungs slows down, which increases the risk of developing respiratory diseases With bacterial complications and others adverse consequences. The skin becomes keratinized, and the limbs are primarily damaged.
Epithelium urinary tract becomes damaged, stones begin to form around fragments of torn tissue. A long-term lack of vitamin A can result in urolithiasis disease and associated complications. Due to a lack of retinol, spermatogenesis in men is disrupted, and testicular tissue atrophy may occur. But a lack of vitamin A is especially dangerous for children and pregnant women.
Risks of retinol deficiency during pregnancy
Pregnant women are at risk. During pregnancy, retinol takes part in the development of many organs and tissues of the fetus. British scientists conducted studies on mice, the results of which established that even a moderate deficiency of retinol increases the synthesis of a protein that destroys brain neurons. These consequences are irreversible.
A lack of retinol during fetal life can lead to decreased ability and early development Alzheimer's disease in mature age. Hypovitaminosis A leads to fading of pregnancy, severe weakness in women, manifests itself as a threat of miscarriage and high risk development of defects in the unborn child.
Be sure to pay attention to your diet while preparing for pregnancy. A large number of vitamin A is found in fish oil, liver, butter, milk, green and yellow vegetables, and legumes. Additionally, take multivitamin complexes.
The role of vitamin A
True vitamin A is retinol (found in animal foods), and its predecessor is carotene “provitamin A” (found in vegetables, fruits, and herbs). In the liver, carotene is converted into vitamin A, and its reserve is in adipose tissue. Thus, even if a person eats poorly for a limited period of time, but has fat throughout the body, there will be no hypovitaminosis. Vitamin A accumulated in adipose tissue will be gradually released, depending on the condition of the body.
Here are the main functions of retinol:
- participation in the production of protein structures, enzymes and hormonal substances;
- maintaining twilight vision;
- participation in skeletal growth;
- staying active reproductive system person;
- preservation of the basic functions of epithelial and bone cells;
- protection against free radicals and premature aging;
- prevention of the development of malignant tumors;
- maintaining full-fledged work genitourinary organs and gastrointestinal tract.
Not long ago, experts discovered the antitumor effect of retinoids. It has been experimentally proven that vitamin A minimizes the effects of carcinogens, maintains the normal functionality of epithelial cells and prevents their proliferation.
Modern research has shown that a lack of vitamin A sharply increases the body's susceptibility to viruses and bacteria. The reason for the development of infections lies in the insufficient intake of retinol from food. Additional Introduction vitamin A helps reduce the risk of measles infection among children, promotes light current diseases.
Vitamin A intake rate
In adults, the need for vitamin A is 700-900 mcg per day. It is enough for a woman to consume 600-700 mcg per day, for a man a little more - about 900 mcg. The norm of vitamin A for a child up to 6 months is 400 mcg, from 6 to 12 months - 500 mcg per day. Children over a year old and adolescents should receive up to 500-900 mcg of vitamin A per day. The need for retinol during pregnancy increases - up to 800-900 mcg per day.
It is important to remember that bile is necessary for the absorption of vitamin A. It is synthesized in the presence of fats in the diet. Low-calorie diets are dangerous for the development of vitamin deficiency, especially for women, who can lose hormonal background and lose previous reproductive functions.
High doses of retinol are toxic! Do not exceed the recommended dosage! But the toxic properties of retinol appear when daily consumption exceeds 3000 mcg.
Products High in Retinol
A decrease in the amount of vitamin A in the blood is observed with an unbalanced diet, when there are no animal products, vegetables and fruits.
It takes several weeks for retinol levels to normalize. Treatment necessarily includes changing your diet and taking vitamin supplements.
Large amounts of retinol are found in the following products:
- beef liver;
- butter;
- egg yolks;
- fish fat;
- sour cream;
- caviar;
- cottage cheese;
Foods high in carotene:
- carrot;
- bell pepper;
- broccoli;
- pumpkin;
- spinach;
- soybeans and peas;
- apricots and peaches;
- sea buckthorn;
- melon;
- rose hip.
How to increase the absorption of vitamin A?
Vitamin A deficiency can be primary or secondary. Primary occurs in children and adults who eat poorly, refuse fruits and vegetables, milk, cheese, cottage cheese and butter, replace healthy dishes semi-finished products, canned food, sweets. Abrupt cessation breastfeeding also increases the risk of vitamin deficiency in a child.
Secondary retinol deficiency is associated primarily with impaired fat absorption and problems in the functioning of organs that are involved in bile formation. Vitamin A is fat soluble and requires adequate fat levels to be absorbed. The absorption of retinol is impaired by a lack of zinc, which is involved in the metabolism and transport of vitamin A.
To increase absorption, vitamin E is also used, which is considered a powerful antioxidant. It promotes the absorption of retinol from the intestines and maintains essential useful properties vitamin A. It is not recommended to use simultaneously with retinol Activated carbon, which may impair absorption useful substances in the intestines.
Vitamin A deficiency - pathological condition associated with a deficiency of a substance in the body. It manifests itself as blurred vision, xerophthalmia, conjunctivitis, dry skin and other symptoms. Lack of vitamin A leads to diseases of the intestines and respiratory tract.
The role and norms of vitamin A in the body
Vitamin A is a fat-soluble substance. It has two forms: carotene (provitamin A, vitamin A2, found in plant foods) and retinol ( original vitamin, A1, comes from animal food). Conversion of carotene into retinol, reserve accumulation occurs in the liver. Additional depot - adipose tissue. The body always has a supply of retinol, which is released when needed.
Retinol performs important functions:
- accelerates oxidative processes;
- slows down aging;
- participates in cell growth, regeneration, formation of dental and bone tissue;
- responsible for maintaining the integrity of the epithelium;
- stimulates the functioning of the immune system and gonads;
- is an antioxidant: protects cells from damage and malignant degeneration;
- is directly involved in the functioning of the visual organs. Vitamin A is a participant in the resynthesis of rhodopsin, a pigment found in rods retina. With a lack of vitamin A, synthesis is disrupted, hemeralopia develops - decreased twilight vision;
- is responsible for normal development embryo.
It is very important for children - it ensures growth and development in accordance with age.
Norms of daily intake (80% of the norm in the form of retinol, the remaining 20% in the form of carotenoids):
- 0-12 months: 0.4 mg;
- 1-3 years: 0.45 mg;
- 4-6 years: 0.5 mg;
- 7-10 years: 0.7 mg;
- 11-50 years: 0.8 mg;
- pregnant women: 0.8 + 0.2 mg;
- nursing mothers: 0.8 + 0.4 mg.
Persons engaged in heavy physical labor, need 1 mg of vitamin daily. This category is included in the risk group for hypovitaminosis A.
Causes of vitamin A deficiency
The level of vitamin A in newborns is low, but in the first days of life it quickly increases due to intake with colostrum, breast milk, adapted mixtures. In healthy children and adults who are on balanced diet, the risk of developing hypo- and vitamin A deficiency is low. What leads to the pathological condition?
- A diet deficient in foods rich in vitamin A. Minimizing milk, vegetables, fruits, butter, eggs, liver, and fats in the diet can lead to deficiency;
- Being on parenteral nutrition;
- Low intake of protein foods. Leads to a lack of protein - a vitamin carrier;
- Impaired absorption of retinol in the intestine with: celiac disease, celiac disease, cholecystitis, spastic colitis, Crohn's disease, diseases of the liver, pancreas, intestines, anemia, alcoholism, cholestasis, disseminated tuberculosis, long-term use mineral oil;
- Loss of vitamin by the body due to: oncological diseases, chronic infections, diseases of the urinary tract;
- Conditions in which there is an intensive consumption of vitamin A: rapid growth and development, pregnancy, lactation, increased physical, mental stress, stress.
Pathogenesis of vitamin A deficiency
The exogenous form of hypovitaminosis A is rare; in general, the condition is secondary - i.e. indirectly by one or another pathology.
Vitamin A deficiency causes pathological change skin, its derivatives and mucous membranes: atrophy of sweat secretions, salivary glands, dry skin and membranes lining the respiratory tract (nostrils, paranasal sinuses, trachea, bronchi). According to some vitaminologists, psoriasis is also associated with hypovitaminosis A.
Signs of Vitamin A Deficiency
They do not develop immediately and indicate severe hypovitaminosis.
- Dryness of the mucous membranes of the mouth and nose;
- Single white spots on the oral mucosa;
- Dryness, flaking of the skin;
- (late symptom);
- Deep cracks in the skin in the area of the knee and elbow joints;
- The appearance of wrinkles, early aging;
- “Goose bumps” on the thighs;
- Acne;
- Severe hair loss;
- Dandruff;
- Fragility of nail plates;
- Deterioration of twilight vision;
- Pain in the eyes in bright light;
- Dryness, dullness of the conjunctiva;
- Corneal keratinization;
- Decreased secretion of the lacrimal glands;
- Iskersky plaques - Bito on the sclera of the eyes;
- In severe cases, necrotic softening of the cornea (keratomalacia), resulting in blindness.
The combination of decreased twilight vision, dryness, clouding of the conjunctiva - reliable sign vitamin A deficiency in the body.
Lack of vitamin A in children is manifested by slow growth, constant fatigue, decreased immunity, dry, pale skin, color blindness, decreased twilight vision.
Nonspecific symptoms of vitamin A deficiency:
- decreased performance,
- insomnia,
- reproductive dysfunction,
- decreased immunity,
- frequent, long-term infectious diseases.
Symptoms of long-term vitamin A deficiency
Long-term hypovitaminosis A leads to vitamin deficiency and serious problems with health:
- dermatitis;
- intestinal infections;
- anemia;
- bronchitis, sinusitis, pneumonia;
- purulent encephalitis;
- cysts in the liver;
- urinary incontinence;
- mastopathy, cervical erosion, thrush in women;
- decreased libido and erection in men;
- chronic infections.
The role of vitamin A deficiency in the development of pancreatic and lung cancer cannot be ruled out.
Diagnosis of its deficiency
The approach to diagnosis is comprehensive.
- Biomicroscopy of the eye (yellowish and white small plaques);
- Determination of vitamin A content in blood serum (normal: 0.3 to 0.8 mcg/ml);
- Study dark adaptation vision (leading symptom).
Treatment of vitamin A deficiency
A diet rich in provitamin and vitamin A is prescribed. If hypovitaminosis is associated with a violation of the diet, this measure is sufficient. It is important to remember that A is a fat-soluble substance: fats are necessary for its absorption and must be present in food. Quitting smoking and alcohol is mandatory. 
- Retinol preparations are prescribed orally or intramuscularly. Daily allowance therapeutic dose 25,000-50,000 IU retinol (rarely at maximum daily dose 100,000 IU). At internal reception the dose is divided into 2-3 doses, with injection- administered by one infection. The course of treatment is 2-4 weeks, in prophylactic doses – 2-3 months.
- The dose of retinol for children is calculated individually according to age, the upper permissible level– no more than 1000 mcg (20,000 IU). Average doses:
- children under one year old 1650 ME;
- children 1-6 years old 3300 ME;
- children from 7 years old 5000 ME.
Vitamin A preparations for children and adults
- Retinol acetate solution in oil, 100,000 IU in 1 ml;
- Retinol acetate (vitamin A in capsules) for children over 18 years of age and adults, 33,000 IU in 1 capsule.
- How to give vitamin A to children? Oil solution- on a piece of black bread. Capsules - whole, washed down with water.
- Vitamin A and E are often prescribed together. A popular drug for children over 14 years of age and adults: Aevit.
Lack and excess of vitamin A are equally dangerous for the body. Long-term treatment retinol in doses of 100,000 IU per day is fraught with the development of hypervitaminosis, which is characterized by: subcutaneous hemorrhages, vomiting, nausea, headache, redness of the skin. Self-treatment and changing the dose without a doctor's prescription is unacceptable.
Sources of vitamin A and carotene/per 100 g. product:
| Products | Retinol (IU) – animal food | Carotene (ME) – plant food |
| Beef liver | 15000 | — |
| Pork liver | 5000 | — |
| Butter | 2000 | — |
| Veal liver | 4000 | — |
| Sour cream | 700 | — |
| Cottage cheese 0% fat | 130 | — |
| Fat cottage cheese | 800 | — |
| Herring | 110 | — |
| Milk | 90 | — |
| Carrot | — | 15000 |
| Parsley | — | 13000 |
| Red rowan | — | 10000 |
| Sorrel | 10000 | |
| Spinach | — | 10000 |
| Green salad | — | 3200 |
| Prunes | — | 2000 |
| Pumpkin | — | 1600 |
| Tomatoes | — | 850 |
| Peas | — | 800 |
| Chanterelles | — | 800 |
| Peaches | — | 750 |
| Apricots | — | 700 |
| White cabbage | — | 630 |
| Green beans | — | 450 |
| Plum | — | 370 |
| Blackberry | — | 300 |
| Green peas | — | 200 |
Prevention
A balanced diet is a simple way to prevent vitamin deficiency for healthy person. For people suffering from diseases that impair the absorption of the vitamin in the intestines, it is important to periodically take retinol preparations in preventive doses (5000-10,000 IU) in courses 2-3 weeks, better than multivitamins ( Vitrum, Duovit, Complivit and etc.).
Consequences
The started process is dangerous due to significant deterioration of vision, malfunction of the immune and digestive systems, premature aging. A lack of vitamin A causes illness and is fraught with a high risk of cancer. To prevent this, at the first sign of vitamin A deficiency, you should consult a doctor.
