Deficiency of which vitamin is responsible for osteomalacia?

The correct answer is Option (4) → D

Vitamins are organic compounds needed in small amounts in the diet; a shortage of a particular vitamin causes a particular deficiency disease:

• Vitamin A — xerophthalmia (hardening of the cornea of the eye), night blindness

• Vitamin B₁ (thiamine) — beriberi; B₂ (riboflavin) — cheilosis, digestive disorders; B₆ (pyridoxine) — convulsions; B₁₂ — pernicious anaemia

• Vitamin C (ascorbic acid) — scurvy (bleeding gums)

• Vitamin D — rickets (bone deformities in children) and osteomalacia (soft bones and joint pain in adults)

• Vitamin E — increased fragility of RBCs and muscular weakness; Vitamin K — increased blood clotting time

So osteomalacia is caused by a deficiency of vitamin D, which is needed to absorb calcium and phosphate for bones.

NCERT (2026-27 edition):
Classification of Vitamins – “… Vitamin D — Sources: Exposure to sunlight, fish and egg yolk — Deficiency diseases: Rickets (bone deformities in children) and osteomalacia (soft bones and joint pain in adults)”