What is the major contributing factor to the development of osteomalacia?

• A. Calcium deficiency
• B. Vitamin D deficiency
• C. Vitamin C deficiency
• D. Excess vitamin A

Answer: (B)

Vitamin D is essential for mineralizing bone. It enables the gut to absorb calcium and phosphate; without enough vitamin D, absorption falls, so the osteoid laid down by osteoblasts isn’t properly mineralized. This defective mineralization makes bone soft and weak, which is the hallmark of osteomalacia in adults. The body may respond with secondary hyperparathyroidism, further accelerating bone turnover and weakening. Among the choices, vitamin D deficiency best explains this pattern. Calcium deficiency can cause problems but doesn’t produce the characteristic defective mineralization; vitamin C deficiency leads to scurvy with different bone changes; excess vitamin A can affect bone but isn’t the primary driver of osteomalacia.