Vitamins are essential to proper body function. They are involved at low concentrations in many vital processes.
Vitamin A is part of the lipid-soluble vitamins, meaning that it is absorbed together with fats. It must be provided by the diet, as the body is unable to produce it.
Where to find vitamin A?
The active form of vitamin A - retinol - is found in animal products including fish oil, liver, butter, tuna, cheese, eggs, etc. This form is directly usable by the body.
In the plant world, vitamin A is found as beta-carotene or provitamin A, both precursors of vitamin A. Beta-carotene must be processed by the body to be activated and used. This process requires fats. It is found in all fruits and vegetables with an orange or red colour
Vitamin A and sports
Vitamin A is involved in many functions that are essential to athletes. It plays a part in the synthesis of retinal pigments. Vitamin A is also involved in cell growth, tissue renewal (skin, intestinal mucosa) and the immune system. It is worth noting that vitamin A promotes iron absorption.
In addition to standard vitamin A properties, beta-carotene can act as an anti-oxidant.
Vitamin A needs
Vitamin A is measured in retinol equivalents (RE). Vitamin A needs amount to 600 to 800 RE / day. It should be noted that 6mg of beta-carotene has an activity equivalent to 1mg of retinol.
An excess of vitamin A is possible, but only in its retinol form, because the body only processes pro-vitamins A into vitamin A based on its needs. An excess leads to digestive disorders.
Deficiency is rare and leads to skin, vision, ossification disorders, and an increased susceptibility to infections.