DECE2-Solution(ENGLISH)-IGNOU-DAY 9-ORSP

Q7. State the important functions of each vitamin in the body.(5 Mark)
Ans. Vitamin A
(1) Maintaining normal vision: Vitamin A plays an important role in maintaining
normal vision. To understand this better, we must first be familiar with the structure
of the eye. The retina has two kinds of cells – rods and cones. Both rods and cones
are sensitive to changes in light but they react differently and perform different
functions. While rods are sensitive to dim light, the cones respond to bright light.
Let us take a closer look at the rods. The rods contain a pigment called rhodopsin.
Rhodopsin is formed by the combination of a specific form of vitamin A with a
protein. The amazing thing about rhodopsin is that it breaks down into its
components when exposed to bright light. In the dark these components – vitamin A
and protein – again combine to regenerate rhodopsin.

(2) Supporting growth: Vitamin A is essential for the growth of the skeleton and soft
tissues. The exact role of the vitamin in the growth of the body is still not
understood. Research studies in this area have indicated that with the deficiency of
vitamin A in the body, bones do not grow to their full length and the overall growth
of the body is affected.
(3) Protecting against disease: Vitamin A plays an important role in keeping
epithelial tissues moist and healthy. Some examples of epithelial tissues are the skin,
the lining of our eyes and the lining of organs like the intestine and lungs. Without
vitamin A the epithelial tissue will become dry and cracks will appear in the skin or
inner walls of the digestive tract or lungs. This makes it easy for the germs to enter
and cause diseases like diarrhea, respiratory infections and eye infections. Various
research studies have supported this and shown that vitamin A plays a beneficial
role in preventing common illnesses in young children. When body levels of vitamin
A are low, the chances are more that the young child will develop, infectious
diseases. If these diseases are sufficiently severe they can even cause death.
Vitamin D:

You might have heard that vitamin D makes bones strong and healthy.
This is absolutely correct. How does vitamin D help in this? Read on to find out.
Minerals like calcium and phosphorus, when deposited in the bones, make them
strong and hard.