What are the Functions of Vitamin A

An Overview

Vitamin A is a group of compounds that perform many vital functions like maintaining proper vision, improving bone growth and other cellular activities like reproduction, cell division, and cell differentiation.

The fat-soluble vitamin A is present only in the food of animal origin, and its provitamin carotenoids are found in plants. Vitamin A plays a vital role in the growth and development of human cells, controlling the immune system by preventing infections and activating white blood cells (WBCs) that destroy harmful pathogens.

This vitamin is also associated with the formation and protection of healthy surface lining areas of the respiratory tract, intestinal tracts and urinary tracts from bacteria and other foreign organisms by causing infections. Vitamin- A helps skin and mucous membranes to function as a barrier to bacteria and viruses. This compound is often referred to as the antixerophthalmic factor or the bright eyes vitamin because of its established role in the visual process.

Explore more: Vitamins And Minerals

Discovery of Vitamin A

It has been observed and recorded that “Hippocrates of Kos”, an ancient Greek (about 500 BC), cured night blindness by prescribing his patients a vitamin- A diet. The activity of vitamin- A was discovered by a nutrition scientist named “Christine Stumbock” in the year 1919. Later in 1917, “McCollum” and “Davis” found the fat-soluble factor in vitamin- A. Later in 1931, the structure of vitamin A was determined by “Karrer”, and its synthesis was achieved in the laboratory by “Kuhn” and “Morris” in 1937.

Also Refer: Scientific Name Of Vitamins

Dietary sources of vitamin – A.

Vitamin A is found naturally in many foods and is obtained from plant and animal sources. These vitamins are stored in fatty tissues and hence are called fat-soluble vitamins.

The preformed Vitamin- A is the source of vitamins obtained from the animals. These are absorbed in the form of retinol. Retinol is the most usable and active form of the vitamin- A. Sources of preformed Vitamin A include liver, fish, poultry, whole milk and other animal products.

The provitamin- A carotenoid is the source of vitamins which are obtained from the plant source that includes colourful fruits and vegetables like green leafy vegetables, sweet potatoes, watermelon, tomatoes, nuts, broccoli and yellow coloured vegetables, such as pumpkin, carrot, bell peppers, corn, squash, etc. Yellow and orange coloured ripe fruits include mangos, guava, papaya, cantaloupe, orange, apricots, etc.

Functions of vitamin- A.

Vitamin A, also known as retinol, is an essential micronutrient necessary for several vital functions. Listed below are a few of them:

It helps in maintaining a proper vision
It is required for a healthy immune system
It helps in the maintenance of epithelial cells
It is also essential for the maintenance of skin and the mucous membrane
It helps in the development and maintenance of teeth, skeletal and soft tissues
Vitamin- A also plays a vital role in regulating and synthesis of proteins and transferrin
Beta-carotene, a form of vitamin A, protects cells from free radicals. This may reduce the risk of cancer.
Vitamin A is also involved in improving skin tone by stimulating the production of new cells and new blood vessels.
In a pregnant woman, vitamin A helps in the formation of healthy skin, eyesight and supports the growth of the foetus
It is involved in the hardening of the cornea in the eye and other eye disorders, such as night blindness, corneal drying, keratomalacia, and other age-related vision diseases.

Along with these functions, vitamin A has been used to treat many other conditions, including cataracts, cancer, and HIV.

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This article concludes with an introduction to the functions of vitamin A.

To know more about vitamins, different types of vitamins, their dietary sources, functions, deficiency diseases, other related topics and important questions on vitamins, keep visiting our website, at BYJU’S Biology.