This fat-soluble vitamin - retinol - is present in foods of animal origin. However, it is also found in the plant, in the form of beta-carotene, which in the body turns into vitamin A (beta-carotene is also called provitamin A). It needs fats to convert to retinol. Research has shown that intramuscular carotene administration is not effective in hypovitaminosis A.
Foods rich in carotene (broccoli, carrot, melon, spinach) are indicated in the case of cancer patients, cardiac patients, those suffering from cataracts or other diseases of old age.
Consumption of fruits and vegetables that contain beta-carotene prevents certain types of cancer from developing: stomach, esophageal, lung or female genital cancer. And other carotenoids (alpha-carotene, lutein, zexanthin, etc.) have a therapeutic action. Beta-carotene supplements do not have a beneficial effect as strong as food.
Recommended daily dose: 3 mg. Some specialists specify that the daily dose required for men should be 3 mg, for women, 2.4 mg, and for children, 1.8 mg.
Sources of Vitamin A
In the form of retinol, vitamin A is found in: pork, beef, veal, fish lard, eggs, non-skimmed dairy products.
Beta-carotene it is found in colorful vegetables such as tomatoes, broccoli, carrot, spinach, asparagus, corn, red beet leaves, papad leaves, melons, mango, apricots, citrus fruits, pumpkin.
Retinol it can oxidize to air, light and is sensitive to cooking, losing its properties. In order to preserve their properties, they must be prepared under certain conditions.
Roles and characteristics of vitamin A
- prevents deterioration of vision; is considered "vitamin of the eyes";
- favors growth;
- helps the immune system to resist tissue and bone infections;
- participates in the metabolism of steroid hormones;
- is beneficial for the treatment of wounds and skin diseases.
Disorders - deficiency or excess
Disorders attributed to vitamin A deficiency
Vitamin A deficiency is not common in developed countries. Problems of assimilation or transformation of carotene (carotene molecules) may occur, especially if the diet is low in fat. People susceptible to vitamin A deficiencies are those suffering from cancer, tuberculosis, pneumonia, urinary tract infections, digestive complications.
The first symptoms that appear in the case of hypovitaminosis are: hemeralopia (diminished visual acuity at night), xerophthalmia, light hypersensitivity, irritation and redness of the eyeball. Also, the lack of appetite, the loss of taste and smell, the formation of kidney stones, allergic manifestations, the degradation of the lining of the intestinal, respiratory and urogenital systems may also occur.
Disorders attributed to excessive consumption of vitamin A
Excessive consumption of vitamin A can produce a series of reactions such as: nervousness, migraines, hypertrophy of the liver, digestive disorders, asthenia, weight loss, vomiting, joint and bone pain.
Pregnant women should use this vitamin with caution; doses greater than 6 mg / day can cause congenital malformations in the fetus, especially in the nervous system. Specialists recommend maximum 1.2 mg / day.
Vitamin A - an important role in our health
Vitamin A is recognized for the following benefits it has on the body: improves vision, stimulates the immune system, fights infections, strengthens the bone system, helps build and strengthen the tooth and prevents acne.
Animal sources of vitamin A:
- beef liver
- whole milk
- goat cheese
- egg yolk
- sea fruits
Vegetable sources of vitamin A:
- sweet potatoes;
- red pepper;
- watermelons red and yellow;
Vitamin A for children
Vitamin A for children is important for the health of the child because it has an important role in stimulating the eyes, in the development of the bones, it ensures the proper functioning of the nervous system and protects it from infections.
The recommended daily dose of vitamin A in children is:
- Babies between 0-6 months: 1320 IU;
- Children 1-3 years: 1240-2310 IU;
- Children 4-8 years: 3000 IU
Recommendation: Before giving your child vitamin A supplements it is advisable to talk with your pediatrician!
- People suffering from acne should not take vitamin A supplement from fish lard, but from other carotenoids;
- It is not advisable to consume the vitamin A several months in a row, even in low quantities, due to its harmful action on the liver;
- Vitamin E promotes the absorption and protection of vitamin A;
- Provitamin A is recommended for smokers because it has effective antioxidant properties, improves vision, increases resistance to infections;
- Women who take birth control pills, people who frequently consume alcohol or have a low fat diet may resort to vitamin A supplements;
Tags Fat-soluble vitamins Vitamin a