Vitamin D deficiency is associated with which of the following conditions?

• A. Vitamin D
• B. Vitamin C
• C. Vitamin A
• D. Vitamin B12

Answer: (A)

Vitamin D is essential for calcium and phosphate absorption and proper bone mineralization. When there’s not enough vitamin D, calcium isn’t absorbed well, leading to poorer bone mineralization and conditions like osteomalacia in adults and rickets in children. The question is pointing to a deficiency that specifically involves vitamin D’s role in bone health, so the best match is Vitamin D. The other vitamins have different primary functions—Vitamin C in collagen synthesis, Vitamin A in vision and immunity, and Vitamin B12 in red blood cell and nervous system function—which don’t explain this bone-related deficiency.