Question

Night blindness is caused due to the deficiency of:
A. Vitamin C
B. Vitamin A
C. Vitamin D
D. Vitamin E

Answer 1

Hint: Deficiency diseases are those diseases which are caused due to the lack of certain vitamins and minerals in our body. Every mineral and nutrient is needed in our body for the various metabolic activities. Metabolism is the sum total of the numerous and various chemical reactions that are going on in our body.

Complete answer:
To know the correct answer to the question, we must be well aware of the various deficiency diseases.
There are certain minerals which are required in large quantities while many are required in very small quantities. The amount of these below certain levels might give rise to deficiency diseases.
Night blindness is one such deficiency disease. It is also known as nyctalopia. The person having this deficiency disease is unable to see at night or in dim light. It is a symptom of a retina disease.

The deficiency disease caused due to the deficiency of vitamin C is known as scurvy. The symptoms of scurvy include anemia, pain in the limbs and debility.
The deficiency disease caused due to the deficiency of vitamin D is rickets. In rickets the bones get very weak, soft or fragile and are prone to breaking very easily.
Abetalipoproteinemia is the deficiency disease caused due to the deficiency of vitamin E in the body. In this disease there is poor absorption of fat and also their metabolism is affected.

So, the correct answer is Vitamin A.

Note: Here it must be noted that there are two main cells present in the retina: the rod cells and the cone cells. The cone cells help us to see things in light while the rod cells help us to see in the dark. In night blindness, these rod cells are affected and so the person cannot see in dark.