It is not for nothing that they say that even the most useful should be in moderation. Even the intake of vitamin components, which we love to replenish so diligently, should be in moderation.
After all, if you drink vitamins uncontrollably, then this can result in the development of hypervitaminosis. And this condition poses a threat to human health.
Vitamin A is used to treat certain diseases; an overdose of this vitamin does not occur often.
Let's take a closer look at what can provoke an overdose, what dose should be ingested in the body to cause an overdose, and how to prevent it? We will deal with all these questions in detail.
Vitamin A contains retinoic acid, retinal and retinol. All these components are not stable, and in order to obtain their stability, they are combined with ethers.
Retinol is present in large quantities in dairy products, in eggs, and in the liver. It can also be found in some vegetables - paprika, tomatoes and carrots. Vitamin A of plant origin is called carotene.
For the human body, the following daily intake of vitamin A is provided:
- For men - 0.9 mg;
- For the fair sex - 0.7 mg.
The maximum allowed daily dose of vitamin A for adults is 3 mg.
For children, the following daily dose is allowed:
- From birth to 1 year - 0.4 mg;
- From 1 year to 3 - 0.45 mg;
- From 4 years to 6 - 0.5 mg;
- From 7 years to 10 - 0.7 mg.
When is an overdose possible?
Vitamin A tends to accumulate in the liver cells. From 10 to 700 mg of this component may be present in the liver. In the liver of animals, this amount is even greater.
If a person in excess eats the liver of domestic animals, liver pate, then vitamin A in large quantities begins to accumulate in the body and its toxic effect occurs.
Interestingly, people who live in the north do not eat the liver of a polar bear, walrus or seal. Even if you eat this product once, an overdose of vitamin A can be fatal.
Often an overdose of this substance occurs:
- When eliminating acne, when drugs such as Tigazon or Roaccutane are used.
- In the treatment of eye diseases in order to restore vision.
- In the treatment of skin diseases, problems with hair, nails, as well as infertility, when the use of Aevit is prescribed.
- An overdose can also occur with prolonged use of fish oil.
- Combined use of vitamin A with medicines containing estrogen.
- In the treatment of infectious diseases and rickets, an increased amount of vitamin A is prescribed. In this case, its accumulation occurs gradually, the symptoms appear over time.
Overdose symptoms
An overdose of vitamin A can occur in acute and chronic forms.
The use of doses from 50 mg to 300 provokes acute intoxication. The person begins to vomit violently, and the vomiting is indomitable. Diarrhea is added to this, resulting in severe dehydration of the body.
From the side of the National Assembly, such symptoms are manifested - headache, convulsive syndrome, visual impairment, confused consciousness.
The next day after taking a large dose, a rash on the skin, peeling occurs. The rash is present on the legs, arms, trunk and face. The bones in the limbs begin to hurt badly.
With an overdose, the feet and palms become yellow in color.
Vitamin A in the normal state is not present in the blood in its pure form. It is associated with protein components. If vitamin A is present in the bloodstream in a free form, then this indicates poisoning with it. If he stays in this form for a long time, then this will provoke a chronic overdose.
The liver suffers most from intoxication, because free vitamin A is very toxic. There is a violation of protein synthesis, which worsens blood clotting. An increased amount of calcium is observed in the blood, which provokes an increase in pressure inside the skull.
Symptoms of high intracranial pressure:
- A person has severe headaches;
- There is nausea, severe vomiting;
- Bones begin to ache;
- Cracks appear in the corners of the mouth;
- Peeling appears on the skin;
- The papilla of the optic nerve swells;
- There is baldness.
Overdose in children
There are frequent cases of poisoning with the vitamin in question among children. The most dangerous complication in this case is the development of hydrocephalus (a condition in which fluid is present in the brain) and bulging fontanelles.
Liver damage occurs, which causes sudden bleeding, the gums begin to bleed, and nosebleeds may bleed.
Consequences of an overdose in a child:
- Body temperature rises;
- There is increased arousal;
- Hair loss begins
- The child's appetite worsens, he may refuse to eat at all;
- There is seborrhea.
Overdose during pregnancy
An overdose of this vitamin in position is a rather dangerous condition. If a woman in position eats normally, then a food overdose is practically unrealistic, because the bioavailability of vitamin A is low.
However, if you combine the intake of products in which this substance is in large doses, together with vitamins in capsules or solution, then the risk of developing congenital malformations in the fetus increases.
The intake of excessive doses of vitamin A during this crucial period threatens the development of heart defects in the baby, a violation in the development of the facial skeleton, stomach defects and other complex consequences.
During pregnancy, the daily intake of vitamin A should not exceed 1 mg..
What to do in case of overdose
If symptoms characteristic of acute intoxication are present, vomiting should be provoked first. After that, perform a gastric lavage and use activated charcoal.
Other important activities are also carried out:
- Ascorbic acid (5 ml) is administered intramuscularly or intravenously.
- The use of hepatoprotective drugs is prescribed.
- Start taking glucocorticoids.
With the simultaneous use of vitamin C and glucocorticoids, the manifestation of an overdose will be reduced.
Hepatoprotective drugs must be taken without fail, because vitamin A is poisonous to the liver, it destroys the cells of this organ. Of the non-traditional methods, milk thistle meal has a good effect.
What to do if overdose symptoms worsen
If the stomach was washed, activated charcoal was drunk, but diarrhea and vomiting did not go away, plus convulsions were added to this, then an ambulance should be urgently called.
A person needs to be taken to a hospital to reduce intracranial pressure. Inpatient treatment includes:
- Intravenous administration of mannitol;
- Intravenous administration of a large amount of glucocorticoids (through a dropper).
conclusions
Vitamin A belongs to the group of fat-soluble vitamins. It is excreted from the body for a long time - 21 days. Its effect on the body is strong, can be compared with the effect of a hormone.
An overdose of this substance is quite dangerous. Don't experiment with it. An overdose of vitamin A of plant origin (carotene) does not pose any danger. Women in position, as well as those who are just planning a pregnancy, should be especially careful when taking vitamin A.
