background: Transfusion dependent β thalassemia is a chronic inherited hemolytic anemia with defective hemoglobin β-chain. Nutritional deficiencies associations are being recognized in recent research. Although it is not fully understood, it might be related to increased nutrients needed, secondary hemochromatosis, endocrinopathies, and decreased Red Cells' life span. The aim of this study is to assess the nutritional deficiencies in Beta thalassemia major. Patients and Methods: A cross-sectional study on fifty transfusion dependent β thalassemia major patients ranging in age from 19 to 42 years old that were recruited from Benha Hematology Outpatient Clinic and Internal Medicine Admission wards, Benha University Hospitals, Egypt from February 2022 to November 2022. Hematological Indices like Hemoglobin, Platelets, and White Blood Cells were evaluated. Ferritin was tested in addition to Vitamin D 3 assay, Parathyroid hormone, Hb A1c, thyroid stimulating hormone, and DEXA scan. Also, extensive nutritional laboratory tests such as serum total protein, albumin, folate, calcium, Phosphorus, and Magnesium were investigated. In addition to height, weight, and routine laboratory evaluation, comprehensive history was taken. Results: Serum Vitamin D, folate and PTH were the most deficient in our studied patients representing 82 %, 28 %, and 20 % respectively. Also, bone mineral density was abnormal in 6 (12%) patients who had either osteopenia or osteoporosis. An increased prevalence of Type 2 Diabetes Mellitus (14%) was noted. No significant association between serum ferritin level and nutritional deficiency was found.