Rickets and night-blindness are caused by the deficiency of ______ and ______, respectively.

Vitamin D, Vitamin A

The correct answer is Option (1)- Vitamin D, Vitamin A

Rickets and night-blindness are caused by the deficiency of Vitamin D and Vitamin A, respectively. Here's an explanation:

1. Rickets (Vitamin D Deficiency):
• Cause: Rickets is a condition that results from a deficiency of Vitamin D, calcium, or phosphate. Vitamin D plays a crucial role in the absorption of calcium and phosphate from the intestines.
• Role of Vitamin D: Vitamin D is essential for maintaining proper bone health. It helps in the absorption of calcium and phosphate, which are necessary for the development and mineralization of bones.
• Symptoms: Rickets can lead to weakened and softened bones, bone deformities, delayed growth, and muscle weakness.
2. Night-Blindness (Vitamin A Deficiency):
• Cause: Night-blindness is primarily caused by a deficiency of Vitamin A, which is crucial for the functioning of the eye's light-sensitive cells (rods and cones) in the retina.
• Role of Vitamin A: Vitamin A is essential for maintaining healthy vision, especially in low-light conditions. It is a component of the light-absorbing pigment rhodopsin, which is necessary for vision in dim light.
• Symptoms: Night-blindness results in difficulty seeing in low-light conditions, and in advanced cases, it can lead to more severe vision problems.