La Vitamin A is belongs to the category of fat-soluble vitamins, ie fat soluble, and through these substances it is distributed throughout the organism. It was named after the first letter of the alphabet because it was the first vitamin to be identified.
> Properties of vitamin A
> Vitamin A food supplements
> Herbal vitamin A supplements
> Vitamin A supplements on the market
> Daily requirement
Properties of vitamin A
Vitamin A occurs naturally as retinol in animal tissues and how carotenoids in plant tissues. There are many carotenoids: about 600 different types have been identified in nature, the most widespread and active of which is the betacarotene. In the body, carotenoids are transformed into retinol in the intestinal mucosa. Vitamin A performs numerous and important functions:
- It is crucial in the mechanism of vision and for the adaptation of the eye to darkness: vitamin A combines with a protein of the retina (opsin) to form rhodopsin, necessary for night vision.
- It is absolutely essential for the bone and tissue formation and for healing, and is the protective vitamin par excellence of skin, mucous membranes, hair and nails.
- Vitamin A promotes growth and, by keeping the skin and mucous membranes (epithelial tissue) functional, increases resistance to infections respiratory, urinary and digestive systems and helps prevent dryness of the conjunctivae and cornea.
- Vitamin A is also used in the dermatological field for the treatment of juvenile acne, psoriasis and has also proved very useful for cholesterol control.
The action of vitamin a is maximum when taken together with: vitamin D, vitamin E, vitamins of the B complex, calcium, phosphorus, zinc (necessary for the mobilization of hepatic retinol).
Vitamin A food supplements
Vitamin A is a fat-soluble (i.e. fat-soluble) vitamin that comes from two sources:
- And Retinoids preformed.
- Pro-vitamin A carotenoids.
Retinoids, such as the retina and retinoic acid, are found in sources of animal origin such as: meats, offal, some fish, eggs, milk, cheeses, butter).
Carotenoids, on the other hand, such as beta-carotene (which represents the greater biological activity of vitamin A), are found in plants, in particular: in yellow-orange vegetables such as carrots, pumpkins, peppers; in green leafy vegetables such as spinach and broccoli; in some fruits such as apricots, melons, yellow peaches, pink grapefruit and papaya.
However, carotenoids are also present in foods of animal origin such as eggs and milk and derivatives. Vitamin A and carotenoids they are resistant to cooking, but sensitive to light and oxygen, so foods that are rich in it should not be stored in the air and sunlight.
You can learn more about the symptoms and causes of vitamin A deficiency
Vitamin A herbal supplements
A good herbal supplement of vitamin A is represented by the Calendula (Calendula officinalis). Marigold is a perennial herbaceous annual plant with orange-yellow flowers. Among its main constituents are high amounts of carotenoids which are the precursors of vitamin A and have one remarkable antioxidant and protective action against free radicals. The mother tincture is prepared from the flowering tops collected in spring and autumn.
Commercial vitamin A supplements
The supplements are in the form of vitamin A or carotenoids. Vitamin A is included in most multivitamins in capsules, tablets or as liquids. They can be found as single supplements, in lower doses in multivitamins, antioxidant supplements, or even protein for women.
Different brands can make them differently, with variable ingredients, even within the same line. It is advisable to always read the labels and to discuss the ideal doses with a doctor before starting therapy.
Il daily requirement of vitamin A it depends on the age and health conditions of the individual. In detail, they are distributed as follows:
- Newborn - 6 months: 400 mcg
- Newborns - 7-12 months: 500 mcg
- Children 1-3 years: 300 mcg
- Children 4-8 years: 400 mcg
- Children 9-13 years: 600 mcg
- Boys 14-18 years: 900 mcg
- Girls 14-18 years old: 700 mcg
- Men: 900 mcg
- Women: 700 mcg
- Pregnant women: 700 mcg
- Breastfeeding women: 950 mcg
A vitamin A deficiency is very rare, as it takes many months of deficient nutrition before i appear deficiency symptoms (brittle nails and hair, dermatitis, impaired night vision), since the body has high reserves of vitamin A in the liver. Some cases require additional vitamin A supplementation, such as:
- Those who follow a low-calorie diet strict, especially if she eats few vegetables.
- Those who consume high amounts of alcohol.
- Smokers, as smoking decreases the absorption of vitamin A.
There may also be cases of hypervitaminosis, i.e. an excess of vitamin A, which is harmful to the body especially during pregnancy. It has in fact been found that the overdose of vitamin A causes fetal malformations.
The properties and benefits of apricots, natural vitamin A supplements
Other articles on vitamin A:
> The 5 foods rich in vitamin A.
> Vitamin A for eye health
> Retinoic acid for wrinkles