Vitamin A is the name for compounds (retinol and retinen) present in food products of animal origin and for carotenoids, found in vegetables and fruits in the form of red and yellow pigment.Vitamin A of animal origin is sensitive to oxidation (rancidity of fats).Sunlight also causes its decomposition.Butter should therefore be stored in light-impermeable packaging and cream in dark or plastic bottles.Cream contains quite a lot of vitamin A but cream only minimal amounts.During whipping it oxidizes due to contact with air.
Excess vitamin A (retinol), accumulates in the liver and can be a cause of poisoning, and in pregnant women can be teratogenic.According to the FDA (Food and Drug Administration) recommendations, a woman planning to become pregnant or pregnant should not take more than 15 thousand.IU retinol per day.This limit applies to all sources of retinol.The above restrictions, however, do not apply to carotenoids, which are stored in adipose tissue and can only be the cause of the reversible, yellow skin color.
The richest sources of retinol are fish fats, liver and its preserves, cream, butter, and egg yolks.100 g of beef liver contains 15,000 IU of retinol while 100 g of pork liver is only 5,000 IU. English experts recommend that pregnant women do not consume more than 50 g of liver per week.
The most common carotenoids are beta-carotene and lipen.1 molecule of beta-carotene is transformed under the influence of intestinal enzymes into two molecules of vitamin A.
The content of beta-carotene in cells is one of the factors stabilizing the balance between the antioxidative processes that protect subcellular structures and oxidizing agents that can damage them.However, it should be emphasized that beta-carotene can not be considered as an anticancer drug, but it is undoubtedly a very important factor inhibiting the dynamics of cancer processes.
As a source of carotenoids, tomatoes rich in lycopene are recommended.Liquopene present in preparations is better absorbed than in fresh tomatoes.The aim of better absorption of this compound by the body is the consumption of vitamin C and E.
Of the more than 600 carotenoids, it was best known
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