Update: October 2018
Vitamin A deficiency is a pathological condition associated with
deficiency of substances in the body. Manifested by deterioration of vision
xerophthalmia, conjunctivitis, dry skin and other symptoms.
Vitamin A deficiency leads to intestinal diseases and
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 to retinol, backup accumulation occurs
in the liver. Additional depot – fatty tissue. In the body always
there is a supply of retinol that is released when needed.
Retinol performs important functions:
- accelerates oxidation processes;
- slows down aging;
- participates in the growth, cell regeneration, dental formation,
- responsible for maintaining the integrity of the epithelium;
- stimulates the immune system, gonads;
- is an antioxidant: protects cells from damage and
- directly involved in the work of the organs of vision.
Vitamin A is a participant in the resynthesis of rhodopsin, a pigment that is available
in the sticks of the retina. With a lack of vitamin A
synthesis is disturbed, hemeralopia develops – decrease
- responsible for the normal development of the embryo.
It is very important for children – it provides growth and development in
according to age.
Norms of its daily receipt (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;
- lactating mothers: 0.8 + 0.4 mg.
Persons engaged in heavy physical labor need 1 mg.
vitamin daily. This category is at risk
Causes of vitamin A deficiency
The level of vit.A in newborns is low, but in the first days of life
rises rapidly due to entry with colostrum, thoracic
milk, adapted mixtures. In healthy children and adults
people who are on a balanced diet, the risk of development
hypo-and avitaminosis A is small. Which leads to pathological
- A diet deficient in foods rich in vit.A. Minimization in
the diet of milk, vegetables, fruits, oils, eggs, liver, fats can
lead to failure;
- Being on parenteral nutrition;
- Low protein intake. Leads to a flaw
protein – vitamin carrier;
- Impaired absorption of retinol in the intestine with: gluten
diseases, celiac disease, cholecystitis, spastic colitis, Crohn’s disease,
diseases of the liver, pancreas, intestines, anemia,
alcoholism, cholestasis, disseminated tuberculosis, prolonged
use of mineral oil;
- Loss of vitamin the body with: cancer,
chronic infections, diseases of the urinary tract;
- States when intensive expenditure occurs
Vit.A: rapid growth and development, pregnancy, lactation, elevated
physical, mental stress, stress.
Pathogenesis of A-vitamin deficiency
Exogenous form of hypovitaminosis A is rare, mainly
the state is secondary – i.e. indirectly one way or another
Vitamin A deficiency causes a pathological change in the skin, its
derivatives and mucous membranes: atrophy of sweat excrement, salivary glands,
dry skin and membranes lining the airways (nostrils,
paranasal sinuses, trachea, bronchi). According to some
vitaminologists, psoriasis is also associated with hypovitaminosis A.
Signs of vitamin A deficiency
Develop not immediately indicate a pronounced
- Dryness of the mucous membranes of the mouth, nose;
- Single white spots on the oral mucosa;
- Dryness, peeling of the skin;
- Yellowish brown skin color (late symptom);
- Deep cracks in the skin in the knee and elbow area
- The appearance of wrinkles, early aging;
- �”Goose skin” on the hips;
- Severe hair loss;
- Fragility of the nail plate;
- Ухудшение twilight view;
- Sore eyes with bright light;
- Dryness, dullness of the conjunctiva;
- Corneal keratinization;
- Reduced secretion of the lacrimal glands;
- Iskersky plaques – Bito on the sclera of the eye;
- In severe cases – necrotic softening of the cornea.
(keratomalacia), ending in blindness.
The combination of reducing twilight vision, dryness, turbidity
conjunctiva – a reliable sign of vitamin A deficiency
The lack of vit.A in children is manifested by growth retardation, constant
fatigue, decreased immunity, dryness, pale skin,
color blindness, the fall of the twilight vision.
Non-specific symptoms of vitamin A deficiency:
- reduced performance
- reproductive impairment,
- reduced immunity
- frequent, long-term infectious diseases.
Symptoms of prolonged A-vitamin deficiency
Prolonged vitamin A deficiency leads to avitaminosis and serious
problems with health:
- intestinal infections;
- bronchitis, sinusitis, pneumonia;
- purulent encephalitis;
- cysts in the liver;
- mastopathy, cervical erosion, thrush in women;
- reduced libido and erections in men;
- chronic infections.
The role of vitamin Vitamin B is not excluded. And in the development of cancer
pancreas and lungs.
Diagnosis of its deficiency
Diagnostic approach is complex.
- Biomicroscopy of the eye (yellowish and white small plaques);
- Determination of vitamin A content in serum (norm: 0.3
up to 0.8 µg / ml);
- The study of dark adaptation of vision (leading symptom).
Vitamin A deficiency treatment
A diet rich in provitamin and vitamin A is prescribed. If
hypovitaminosis is associated with a violation of the diet, this measure happens
enough It is important to remember that A is a fat soluble substance:
Fats are necessary for its absorption and must be present in food.
Mandatory refusal of smoking, alcohol.
- Retinol preparations are prescribed by mouth or intramuscularly. Daily
therapeutic dose of 25 000-50 000 ME retinol (rarely in
максимальной суточной дозе 100 000 МЕ). With internal reception
the dose is divided into 2-3 doses, with injecting – one is administered
infection. The course of treatment is 2-4 weeks, in preventive
doses – 2-3 months.
- The dose of retinol for children is calculated individually by
age, the upper permissible level is not more than 1000 mcg (20 000
ME). Medium doses:
- children up to year 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 oil solution, 100 000 ME in 1 ml;
- Retinol acetate (vitamin A capsules) for children from 18 years and
adults, 33,000 IU in 1 capsule.
- How to give children vitamin A? Oil solution – on a piece
black bread. Capsules – entirely with water.
- Vitamin A and E are often prescribed together. Popular drug for
children from 14 years and adults: Aevit.
Lack and excess of vitamin A are equally dangerous to the body.
Long-term treatment with retinol in doses of 100,000 ME per day is fraught
development of hypervitaminosis, which is characterized by: subcutaneous
hemorrhages, vomiting, nausea, headache, skin redness.
Self-treatment and dose change without a doctor’s prescription
are not allowed.
Sources of vitamin A and carotene / 100 gr. product:
|Products||Retinol (IU) – animal food||Carotene (IU) – plant food|
|0% fat cottage cheese||130||–|
|Fat cottage cheese||800||–|
|Mountain ash red||–||10,000|
|Green String Beans||–||450|
Rational nutrition – a simple way to prevent deficiency
vitamin for a healthy person. For people suffering
diseases that affect the absorption of vitamin in the intestine,
actual periodic administration of retinol in prophylactic
дозах (5000-10 000 ME) курсами по 2-3 недели,
лучше поливитаминных (Витрум, Дуовит, Компливит и
Running the process is dangerous significant visual impairment, failure
in the work of the immune, digestive systems, premature
aging Vitamin A deficiency causes illness and is fraught with high
risk of oncology. To prevent this, at the first sign
vitamin A deficiency should consult a doctor.
Автор: врач-гигиенист, эпидемиолог