Vitamin A- The definition and source of Vitamin A: The
body fat stores Vitamin A which is soluble in fats. Vitamin A supplement
is not required to be taken daily though it is essential for the human
body. The human liver stores almost 90 per cent of Vitamin A. Vitamin
A is mainly found in two forms: the preformed Vitamin A known as Retinol
or Beta Carotene known as Retinoids. Beta Carotene is the predecessor
of Vitamin A which is formed in the human intestine, liver and the kidneys.
Deep yellow and deep green leafy vegetables as well as fish liver oils,
egg yolk, liver and fortified foods like milk or margarine are full of
The function and the scientific study evidences of Vitamin A:
Vitamin A is essential for combination of photoreceptor pigments of rods
and cones, reliability of skin and mucosae, normal tooth and bone development,
normal reproductive capabilities as well as it has vital antioxidant properties.
It also promotes forming rhodopsin substance which is especially required
for better night vision. Vitamin A also helps in maintaining membranes,
inner-linings, tissues, skin and eyes in proper state. It energizes cells
in immune system and also acts as the antioxidant. It is better to prevent
free radicals before they stop you.
Recommended dosage and its side effects: The recommended
dosage of Vitamin A for male is 5000 IU or 1.5 mg and for female 4000
IU. However, Vitamin A dosage of more than 50,000 IU can always be toxicating
and causing severe damage to vital organs of the body. For getting the
best results prefer to remain within suggested dosage. Whereas Beta Carotene
is considered non-toxic even if taken in higher doses as body transforms
only the required quantum to Vitamin A; but however the maximum level
of Beta Carotene dose is supposed to be 17,500 IU. The medicinal interactions
include lesser effect of Phenytoin and enhance Oral anticoagulants effects.