Correct Option
The correct option is (a).
Explanation
Rickets is a skeletal disorder that primarily affects children. It is characterized by defective mineralization of bones due to a deficiency in Vitamin D, calcium, or phosphate. This condition leads to the softening and weakening of the skeletal structure.
Statement-wise Analysis
- Statement 1 is Correct: Rickets is primarily caused by a prolonged deficiency of Vitamin D. Vitamin D is essential for the body to absorb calcium and phosphorus from the gastrointestinal tract. Without sufficient Vitamin D, proper bone mineralization cannot occur.
- Statement 2 is Incorrect: Rickets results in bones becoming soft and weak, not hard and brittle. This softening leads to skeletal deformities such as bowed legs, knock knees, and pigeon chest. Hard and brittle bones are typically associated with other conditions, whereas Rickets (and Osteomalacia in adults) is defined by the lack of hardness.
- Statement 3 is Incorrect: Rickets affects the skeletal system (bones). It does not affect the glands in the neck. The enlargement of the thyroid gland in the neck is a symptom of Goitre, which is caused by Iodine deficiency.
Key Takeaway
Rickets is a deficiency disease caused by a lack of Vitamin D, Calcium, or Phosphorus, leading to the softening and deformation of bones in children.