Adolescents and young adults undergoing spinal fusion surgery for the correction of scoliosis and other spinal deformity are at high risk of perioperative iron deficiency and anemia, yet the means and evidence for optimizing iron status have not been described in this setting. The proposed study is a randomized controlled trial of preoperative intravenous iron supplementation, to identify whether iron deficiency is a modifiable risk factor for adverse surgical outcomes such as red blood cell transfusion and diminished postoperative cognitive and physical capacity in this vulnerable population. Building evidence for patient blood management interventions such as iron supplementation is vital to ensuring high quality care of surgical patients and may reduce unnecessary transfusions amid recent blood shortages.