What is vitamin A for?
Vitamin A is the most important component of the proper functioning of the immune system and the maintenance of a healthy metabolism. In the form of retinol, vitamin A is part of most tissues of the human body (starting from bones, internal organs and muscles, ending with skin, hair and teeth), regulating all kinds of healing and growth processes.
The most important property of vitamin A is the ability to bind free radicals to limit their negative effects, as well as the ability to slow down the aging and growth of cancer cells. Among other things, vitamin A enhances the effects of various antioxidants (e.g., vitamin C and vitamin E).
Vitamin A for skin health
Retinol (Vitamin A 1 ) is necessary for skin tissues and mucous membranes both to maintain health and to recover from damage. One of the key functions of retinol is to improve the synthesis of collagen, a building material for the connective tissues of the body. Recall that with age, the amount of collagen in the body decreases.
It is thanks to this factor that retinoids, which are a synthetic analogue of vitamin A, are found in many cosmetics for treating the skin and prolonging its youth - from anti-aging creams and lotions against sunburn, to pharmacy preparations for acne and even creams for stretch marks.
Daily Vitamin A Requirement
For adult men, the daily requirement for vitamin A is 900 mcg (equivalent to 3000 IU), for adult women - 700 mcg (2300 IU). Adolescents require about 600 micrograms of this vitamin (2000 IU), and small children - 300-400 micrograms (1) . During pregnancy and breastfeeding, a woman’s need for vitamin A usually increases.
It should be noted that vitamin A can accumulate in the tissues of the body - in other words, its regular use in excessive quantities leads to intoxication. The upper limit of the safe daily dose is 3000 mcg for adults and 900 mcg for children. The safe limit for single use is about 9000 mcg.
Vitamin A deficiency: symptoms
A typical “urban” diet consisting of semi-finished meat products (sausages, meatballs) and various grains (ranging from bread and pasta, ending with white rice and even buckwheat) can easily form a lack of vitamin A. It is also important that the use of low-fat foods exacerbates the situation. since it also removes vitamin A.
A chronic lack of this vitamin in the diet affects a comprehensive decrease in human immunity, the frequent incidence of colds and other infectious diseases, and visual impairment (especially in the dark). The skin becomes dry and begins to crack, hair and nails lose their hardness and shine, dandruff appears.
Beta Carotene Content in Products
In nature, there are several variations of vitamin A that differ in chemical structure and have a different percentage of assimilation for the human body. The initial vitamin A is found mainly in animal products - in caviar, liver of fish and animals, chicken eggs, all kinds of cheese, butter, fat cottage cheese, whole milk.
Vegetables and fruits contain beta-carotene, which is converted to vitamin A during digestion. However, it is important to know that the level of assimilation of such beta-carotene is significantly lower than the level of assimilation of animal vitamin A - 1 μg of beta-carotene from carrots or pumpkins is equal to 1/12 or even 1/24 μg of retinol from the liver of marine fish.
Vitamin A Tables
Carefully read the table of vitamin A content in foods - if you do not receive 100% of the daily intake with food, you should consider reviewing your diet or taking this vitamin in capsules. However, remember that excessive consumption of vitamin A in tablets leads to intoxication and can be dangerous.
Vitamin A is fat-soluble, therefore it is absorbed exclusively when taken with oil or other fats - it is usually sold in special capsules that already contain the required dose of vegetable fat for optimal absorption. However, when taking vitamin A in tablets, it is important to remember contraindications. How to take vitamin A capsules: instructions
The simultaneous use of this vitamin in the form of dietary supplements and as part of any other drugs (for example, anti-aging cream for the skin) can gradually lead to overdose and intoxication. In addition, taking vitamin A in capsules is incompatible with the course of antibiotic treatment or taking various anticoagulants.
Vitamin A is needed by the human body to maintain a healthy immunity and ensure the proper functioning of cells of various tissues. Most of this vitamin is found in cod liver, sweet red pepper, carrots and sweet potato . With a lack of vitamin A in a daily diet, it is recommended to take it in the form of dietary supplements in capsules.
Sources of scientific data:
- Vitamin A, The New Your Times Health Guide, source
- Vitamin A: Fact Sheet for Health Professionals, source
- National Nutrient Database for Standard Reference, source