Rickets is prevented by intake of which vitamin?

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

Answer: (D)

Rickets is a bone mineralization problem in growing children caused by too little vitamin D, which is needed to absorb calcium and phosphate from the gut. Vitamin D’s key role is to boost the intestine’s absorption of these minerals, supplying the material bones need to form hydroxyapatite crystals. When enough vitamin D is available, calcium and phosphate enter the bloodstream and bones mineralize properly, preventing the soft, bent bones seen in rickets. You can get vitamin D from sun exposure and fortified foods, as well as supplements if needed.

The other vitamins don’t directly enable this mineralization process: vitamin C is mainly about collagen formation, not mineral absorption; vitamin A influences growth and remodeling but isn’t the thing that prevents rickets; vitamin K helps bone proteins but doesn’t play the primary preventive role that vitamin D does.