AimsIncreased oxidative stress in diabetes mellitus may lead to splenic damage, contributing to decreased immunity. This study aims to evaluate the potential of vitamin E supplements as a protective agent against spleen injury by examining physiological, hematological, biochemical, and histological changes in diabetic rat model. MethodsDiabetes was induced in male wistar albino rats through an intraperitoneal injection of 50mg/kg Streptozotocin, and the rats were randomly divided into five groups. The rats were then administered varying doses of vitamin E for 14 consecutive days. Assessments included renal function tests, blood glucose levels, complete blood counts, lipid profiles, tissue oxidative stress and spleen histology. An acute toxicity study was also conducted on normal rats. ResultsVitamin E supplementation did not result in any mortality up to 5000mg/kg body weight. The treated diabetic group showed improved metabolic characteristics, such as normal body weight, food and water intake and a reduced spleen index compared to the untreated diabetic group. Significant improvements were observed in hematological parameters like packed cell volume (PCV), hemoglobin concentration, RBC (red blood cells) and WBC (white blood cells) counts. HCA (Hierarchical Cluster Analysis) of these parameters indicated that doses of 100mg/kg and 150mg/kg were most similar to normal condition. Catalase and MDA (Malondialdehyde) assays showed a substantial reduction in oxidative stress in spleen tissue and histopathological examination revealed significant regenerative effects. ConclusionThis study demonstrated that vitamin E supplementation significantly enhanced various metabolic, hematological, biochemical, and histological parameters in the diabetic group compared to those who did not receive the treatment. Among the doses tested, 100mg/kg and 150mg/kg body weight were found to yield the most favorable outcomes.