Due to the spread of corona virus, many doctors' advice people to take vitamin D to prevent catching corona virus. But some people used it carelessly without keeping out the consequences of toxicity. For this reason, this study concerns on the impact of vitamin D overdose in mice on the expression of different important genes (VDR, TRPV6 and CYP3A11 genes), histopathological legions, and biochemical properties. Forty male Albino mice, each male weighs 35-40 mg, were divided randomly to four group each group contain 10 mice. Each group were treated daily with a different concentration of Vitamin D for 8 weeks by a stomach tube. The Groups were control (without Vitamin D), low dose (1um of Vitamin D /ml), intermediate dose (2 um of Vitamin D /ml), high dose (3 um of Vitamin D /ml). After 8 weeks, the mice were slaughter and different tissues were examined. Results showed that vitamin D overdose caused up regulation in the VDR gene expression, and down regulation in both TRPV6 and CYP3A11 genes. Moreover, vitamin D overdose caused significant histopathological changes that were observed in different tissues as stomach, heart, lung and kidney. Biochemical properties were investigated to test the liver function by measuring the ALT, and AST enzymes. While the Kidney function were examined by measuring BUN, vitamin D and calcium levels. The biochemical tests illustrated that vitamin D overdose caused raised level of total calcium, BUN, ALT and AST enzyme in blood. These signs referred to damage of kidney and liver relatively.