All About Vitamin A



Vitamin A, also known as β- carotene or retinol, is the first of all the vitamins to be discovered by Funk and hence it is called vitamin A. It is derived from both animal and vegetable sources. Its main role is to aid in normal vision and healthy skin. Also it is used as an enhancer of our immune system.


Sources of vitamin A


Sources of vitamin A are divided into two forms: animal sources and vitamin sources. Therefore one should have both vegetarian and non vegetarian foods to meet the supply of vitamin A in the body.


Animal Sources of Vitamin A


Animal sources of vitamin A are fish liver oil, liver, fishes, eggs etc.



Vegetables Sources of Vitamin A


Vegetables rich in vitamin A include carrots, sweet potatoes, and pumpkin, dark green leafy veggies like spinach and fruits like mangoes, papaya and cantaloupe. Apart from this, tomatoes and green beans are also richly supplied with vitamin A.


The minimum dose of vitamin A required by males and females is 5,000 IU per day and 4,000 IU per day respectively.


Health Benefits of vitamin A


Vitamin A comes with endless health benefits but its main role is in maintaining of good eye sight. Let us have a good look at the benefits of vitamin A.



Healthy Eye Sight: Vitamin A is quite useful for night vision. Vitamin A is rich supplier of retinal that combines with opsin to form rhodopsin, pigment that helps in night vision.


Prevents Cataract: Cataract is the cloudy appearance of eye lens that is seen due to the free radical damage. Having diet rich in carotenoids (beta carotene) fights against the free radicals and hence prevents cataract formation.


Strengthens Immunity: Vitamin A aids in the development of lymphocytes, the cells that boosts our immune system and fights against the foreign bacteria.


Vitamin A Acts as an Anti-Oxidant: Carotenes present in vitamin A act as an anti oxidant. It prevents free radical damage by destroying the free radicals and thus decreases the aging process as done by vitamin C.


Vitamin A and Cancer: Various studies have shown that vitamin A can fight against prostate and colorectal cancer.



Deficiency of Vitamin A


Vitamin A deficiency occurs when our diet is poorly supplied with vitamin A and beta carotenes.


Night Blindness: The main disease associated with the deficiency of vitamin A is night blindness i.e. difficulty to see in dim light. This is due to the damage to rod cells that helps in dim night vision.



Keratomalacia: In this disease, there is ulcer formation in the cornea. Cornea becomes dry and there is degradation of its epithelium and finally all this leads to opacity in cornea.


Xeropthalmia: Here the eye balls become dry and thick due to the deficiency of vitamin A. If it persists for a longer time, then it leads to Keratomalacia.


Excess of vitamin A


Recommended dietary intake of vitamin A is 800 mcg and 1000 mcg for females and males respectively. Taking vitamin A in excess can lead to nausea, blurred vision, irritation and increased fractures (in case of post menopausal women). It can also lead to alopecia, spleenomegaly, hepatomegaly and stunted growth.

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