Objectives: To study Vitamin D levels and bone age estimation in patients with thalassemia major and to correlate various factors associated with short stature, Vitamin D deficiency and bone age difference. Study Design: Prospective observational study Setting: Thalassemia clinic, Civil hospital, Ahmedabad Subjects and intervention: Total 84 patients with Beta-thalassemia major less than 12 years of age during 1 month period were included after taking informed consent. Study period: 15 October 2016 to 15 November 2016 Results: Out of 84 patients 34 patients had Vitamin D deficiency(<20ng/ml), 34 patients had short stature and 24 patients with bone age >36 months had age>10 years. Vitamin D levels <30ng/ml is associated with ferritin level >2500(mcg/l)(OR=2.23 p=0.02 95%CI). Age>10 year(OR=7.7 P=0.0001 95%CI) and ferritin >2500mcg/l (OR=1.9 P=0.1 95%CI)are associated with bone age difference>36 months. Increased S.ALP(OR=1.1 P=0.02 95%CI) and ferritin levels>2500 mcg/l (OR:3.6 P=0.0056 95% CI)are associated with short stature. Conclusion: Vitamin D and calcium supplementation along with disciplined transfusion and chelation regimen can likely prevent or delay late complications like short stature, osteoporosis in thalassemia patients.