VDR and systemic lupus erythematosus: HE staining and PAS staining illustrated that the morphologies of the renal tissues in the control group and VDR−/− group were normal at 0 W, while the renal tissues of SLE mice (in the SLE, SLE + VD3, and SLE + VD3 + VDRinsert groups) exhibited signs of damage, i.e. increased glomerular volume, deposition of fuchsinophilic proteins in the mesangial area and subendothelial area, infiltration of chronic inflammatory cells in the glomerulus and renal interstitium, with signs of monocyte infiltration of the glomerular capillary.