PPAT and diabetic kidney disease: In addition, vitamin D stimulated the expression of the surface markers PGC1α, UCP-1 and VDR in the PRAT in DKD mice, and TMAO downregulated the expression of PRAT and renal VDR.<h4>Conclusions</h4>The protective effect of 1,25-(OH)<sub>2</sub>D<sub>3</sub> in DKD mice may affect the intestinal flora and its related metabolite TMAO on perirenal fat and kidneys.