Effect of Vitamin A Supplementation on Idiopathic Scoliosis

Inclusion Criteria: 1. Age between 6 and 15 years. 2. Biochemically confirmed vitamin A deficiency (serum retinol \< 0.20 mg/L) or insufficiency (serum retinol 0.20-0.29 mg/L). 3. Has undergone radiographic evaluation (standing full-spine X-ray) for idiopathic scoliosis at the initial clinic visit. 4. Skeletally immature (Risser sign 0-3) with a major Cobb angle \< 40 degrees at baseline. 5. Written informed consent/assent provided by the participant and legal guardian. Exclusion Criteria: 1. Unwillingness or inability to comply with all study procedures and follow-up visits. 2. Plans to relocate outside the study area within the next 24 months. 3. Previous high-dose vitamin A supplementation therapy within the past 12 months. 4. Clinical signs of severe vitamin A deficiency syndrome (e.g., xerophthalmia, Bitot's spots). 5. Serum vitamin A level \> 0.70 mg/L (to avoid risk of hypervitaminosis A). 6. Severe chronic health conditions that could confound study outcomes, including but not limited to: * Known syndromic, neuromuscular, or congenital musculoskeletal causes of scoliosis. * History of spine surgery or significant spinal trauma. * Spinal tumor. * Leg length discrepancy \> 20 mm. * Other severe chronic diseases (e.g., poorly controlled diabetes, chronic liver or renal disease, malabsorption syndromes). * Severe obesity (body mass index z-score ≥ 3).