维生素D主要生物活性形式是1,25-(OH)_2-D_3,后者具有维持体内钙磷动态平衡,调节骨代谢和促进多种组织细胞生长、分化等多种生物功能。这些功能的实现需要通过1,25-(OH)_2-D_3与活化的细胞核内受体即维生素D受体(VDR)相结合,从而调节维生素D靶基因的转录水平来发挥作用。研究表明VDR基因存在多个多态性位点,各基因型在不同种族之间分布频 The main biologically active form of vitamin D is 1,25- (OH) _2-D_3, which has many biological functions such as maintaining the balance of calcium and phosphorus in the body, regulating bone metabolism and promoting the growth and differentiation of various tissue cells. These functions need to be mediated through the binding of 1,25- (OH) 2-D_3 to the activated nuclear receptor, vitamin D receptor (VDR), to regulate the transcriptional level of vitamin D target genes. Studies have shown that there are multiple polymorphic sites of VDR gene, the genotypes in different races frequency distribution