Abstract: Objective To observe the effects of vitamin D₃ (VitD₃) at toxic dose on the blood and renal biochemical indicators of rats. Methods The specific pathogen free SD rats were randomly divided into five groups: control group, low dose VitD₃ group (1 875 IU), medium dose VitD₃ group (3 750 IU ), high dose VitD₃ group (7 500 IU), and super high-doseVitD₃ group (15 000 IU). They were intragastric administration once a day for 3 weeks.The relevant indicators were detected after treatment finished. Results Serum blood urea nitrogen (BUN) and Creatinine (Cre) decreased significantly with the dose decreasing, and the content of serum Ca²⁺ increased significantly with the dose increasing. The content of superoxide dismutase (SOD), and serum malondialdehyde (MDA) decreased with the dose increasing. In renal tissue, the content of Ca²⁺ gradually increased with the dose increasing, and there was no significant difference in MDA at the dose of 1 875 IU and 7 500 IU. Conclusions At the dose of 1 875 IU to 15 000 IU, VitD₃ has significant effects on the renal biochemical indicators such as BUN, Cre and serum Ca²⁺, indicate that the dose range 1 875 IU to 15 000 IU can induce renal toxicity in experimental rats.

Key words: Vitamin D₃(VitD₃), Rats, Toxic dose, Kidney