Question

Rickets results from impaired _______.

• A. iron metabolism
• B. calcium absorption
• C. protein synthesis
• D. fat digestion

Hint:

While rickets is commonly associated with a lack of Vitamin D, the actual physical cause of the bone weakness is the resulting failure to absorb calcium.

Answer 1

The Correct Option is B

Step 1: Understanding the Question:
The question asks for the specific physiological impairment that leads to the development of rickets in growing children.

Step 2: Key Concepts and Approach:
Rickets is a skeletal disorder characterized by soft, weak bones in children.
Normal bone development requires the continuous deposition of calcium and phosphorus into the bone matrix (mineralization).

Step 3: Detailed Explanation:

• Role of Vitamin D: Vitamin D (calcitriol) is essential for the active transport and absorption of dietary calcium across the intestinal wall.

• Impairment Mechanism: When there is a deficiency of Vitamin D (or a genetic defect in its receptor), the active absorption of calcium in the gut is severely reduced.

• Systemic Response: Low blood calcium levels trigger the release of parathyroid hormone (PTH).
PTH stimulates the release of calcium from bones into the bloodstream to maintain vital functions, leading to bone demineralization.

• Skeletal Symptoms: As a result, the growing bones of children remain soft, leading to structural deformities like bowed legs and skeletal weakness.

Step 4: Final Answer:
Rickets directly results from impaired calcium absorption.