Vitamin A or retinol is a fat-soluble substance stored in body organs, principally the liver.
It is released as needed into bloodstream, becoming available for use by cells throughout the body, including those of the eye. It has important functions related to vision and reproduction.
Vitamin A deficiency occurs in persons with poor diet and lacking vegetables. When there is depletion of vitamin A in liver, the earliest sign is night blindness that is impaired dark of adaptation.
Xerophthalmia is caused by deficiency of vitamin A. Xerophthalmia is a term to cover all the ocular manifestation of vitamin A deficiency, including not only the structural changes affecting the conjunctiva cornea and occasionally retina, but also the biophysical disorders of retinal rod and cone function that are attributable to vitamin A deficiency.
It produces one or more severe eye diseases/disorders.
While adults store vitamin A in liver, the infants do not possess adequate stores of vitamin A. Xerophthalmia thus affects large number of children but rarely adults.
If not treated in time, it can lead to permanent blindness.
Xerophthalmia and vitamin A deficiency
Vitamins are defined as a group of complex organic compounds present in minute amounts in natural foodstuff that are essential to normal metabolism and lack of which in the diet causes deficiency diseases. Vitamins are required in trace amounts (micrograms to milligrams per day) in the diet for health, growth and reproduction.
Wednesday, June 5, 2013
Most Popular Articles
-
Classification of Vitamins Classically, vitamins have been divided into two groups based on their solubilities in fat solvents or in water...
-
Vitamin K and Its Role in Our Body Vitamin K denotes a group of lipophilic, hydrophobic vitamins that are needed for the posttranslational ...
-
Vitamin C: Function and Action Despite its uncomplicated structure, vitamin C apparently has a very complex functional role in the body. Al...
-
Ascorbic acid function as antioxidant L-ascorbic acid, its salts (sodium-L-ascorbic and calcium-L-ascorbate), and its isomers (D- and L-isoa...
-
Casimir Funk: the Father of Vitamins Vitamins are s much a part of modern life you may have a hard time believing they are first discovered...