Vitamin D is a crucial element in the body that plays a pivotal role in health and disease, and it can be obtained either through food or direct exposure to sunlight. This study aimed to detect the histological effect of vitamin D3 overdose on liver and kidney tissues. The experiment included sixteen female rats which were distributed into four groups, each group containing 4 rats, Group1: control was given only olives oil Group2: 0.5ml of D3 + 9.5ml olives oil, Group3: 1ml D3+9ml olives oil Group4: 2ml D3+8ml olives oil, the experiment continued for30days, After end the period, the rats were sacrificed and obtained the organs. The results showed High doses of Vitamin D3 can cause pathological histological changes in the liver and kidneys due to increased calcium deposition and inflammatory effects. The most elevations were in group 4 which was considered high dose. This elevation included: Tubular Calcification and tubular Degeneration, of the kidney, and for the liver the results showed Congestion of Liver Blood Vessels and Hepatocellular Degeneration.