Question

Deficiency of which of the following essential vitamins in the human diet causes a reduction in intestinal calcium absorption, leading to the bone-softening childhood skeletal deformity known as Rickets?

• A. Vitamin A
• B. Vitamin C
• C. Vitamin K
• D. Vitamin D

Hint:

Keep this quick summary of common NCERT vitamin deficiencies memorized:

• Vitamin A deficiency = Night Blindness
• Vitamin C deficiency = Scurvy (bleeding gums)
• Vitamin D deficiency = Rickets (bone softening)
• Vitamin K deficiency = Increased blood clotting time (hemorrhage)

Answer 1

The Correct Option is D

Concept: Vitamins are essential organic micro-nutrients required in small amounts to carry out vital metabolic and physiological functions within the human body. They are broadly classified into fat-soluble vitamins (A, D, E, K) and water-soluble vitamins (B-complex, C).

Step 1: Analyze the physiological function of Vitamin D.
Vitamin D (calciferol) is a fat-soluble vitamin that plays a vital role in maintaining skeletal health by regulating calcium and phosphorus absorption in the intestines. It can be synthesized by the body when skin is exposed to solar ultraviolet radiation.

Step 2: Link a deficiency in this vitamin to its clinical symptoms.
A deficiency in Vitamin D impairs the body's ability to calcify and harden bone tissue. In children, this structural weakness leads to Rickets, a deformity characterized by soft, bowed legs and malformed joints. In adults, this same deficiency leads to a condition known as osteomalacia.