Vitamin A – Function, Need, Deficiency and Overdose

What is vitamin A?

Vitamin A refers to a group of compounds that are vital for us and all other vertebrates. The most important of these compounds is retinol. However, this also includes chemical compounds closely related to retinol, which are grouped together as retinoids. These are found in animal foods.

But vitamin A is also found in plant foods, in the form of carotenes. However, the body cannot absorb these directly, they are only converted into retinoids.

What is the function of vitamin A in the body?

Vitamin A is very important for the visual process. Here it helps us to distinguish between light and dark, especially at night.

It also plays an important role in reproduction and the development of the embryo, where it mainly supports the development and maturation of the lungs.

The immune system also needs vitamin A to form immune cells. In addition, the vitamin is needed for the healthy growth of cells and tissues.

Daily requirement vitamin A

The recommended daily reference values for the intake of vitamin A according to the German Nutrition Society (DGE) can be summarized for non-scientists as follows:

Age groupReference value vitamin A per day
Infants (0-4 months)500 micrograms
Infants (4-12 months)400 micrograms
Children (1-7 years)300-350 micrograms
Children (7-10 years)450 micrograms
Adolescents (10-19 years)600-800 micrograms
Adults (19 years and older)700-850 micrograms
Breastfeeding1300 micrograms
Simplified table

These recommendations apply to healthy individuals and may vary depending on individual needs, medical conditions, or pregnancy. Breastfeeding women in particular have an increased need.

Who has an increased need for vitamin A?

Pregnant women from the 4th month have an increased need for vitamin A and should pay attention to an increased intake. The need for breastfeeding is also increased, as the vitamin is needed for embryonic development, but also for healthy growth.

Too much intake can also be harmful to the embryo, especially in the first trimester, it is not recommended to take dietary supplements. For example, care should also be taken not to eat liver or not too much.

Care should also be taken to ensure a balanced diet and sufficient vitamin A intake in children, as the vitamin is very important for growth.

How does vitamin A deficiency manifest itself?

Symptoms of vitamin A deficiency include blurred vision. These can vary in severity, for example as night blindness, a reduction in visual acuity, sensitivity to light or dry eyes.

But there are many other symptoms such as: increased susceptibility to infection, hair loss, fatigue and growth disorders such as disorders of bone growth in childhood. In addition, increased risk of cancer in organs with mucous membranes, increased risk of kidney stones.

Causes of vitamin A deficiency

Vitamin A deficiency can have various causes. Most often, an unbalanced diet, and thus too little intake, leads to a deficiency.

But it can also lead to difficult absorption due to gastrointestinal diseases. With increased alcohol consumption, the body is no longer able to store sufficient vitamin A. And as mentioned above, it is easy to become deficient during pregnancy.

Foods that contain a lot of vitamin A

Most vitamin A is found in the liver, as it is stored there by us and all other vertebrates. Other animal products with a lot of vitamin A are: eggs, dairy products, especially butter and cream, and fish, especially eel and tuna.

In the case of fruits and vegetables, there is a particularly high amount of vitamin A in carrots, savoy cabbage and spinach. But kale and apricots also have a high content. In addition, the herbs parsley and dill are at the top.

Interactions with other nutrients and medications

There are no known serious drug or other nutrient interactions. But still, discuss any medication and supplement intake with your doctor

Overdose of vitamin A

An overdose due to a balanced diet cannot occur. The intake of dietary supplements, in the form of tablets or capsules, should always be discussed with a doctor, as it can easily lead to too high an intake. Both if you want to have children and in the first months of pregnancy, this should be completely avoided.

Symptoms may include headache, nausea, and vomiting. With a prolonged overdose, sleep disturbances, irritability, loss of appetite, dry skin and mucous membranes, and hair loss, among other things, occur.

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