VDR and intestinal disorder: Finally, vitamin D in the intestine, through its active form binding to the vitamin D receptor (VDR), performs various functions by augmenting calcium and phosphate absorption, fortifying epithelial barrier integrity via the upregulation of tight junction proteins and antimicrobial peptides, modulating innate and adaptive immune responses to maintain homeostasis, and fostering a balanced microbiota to safeguard against inflammation, infection, and intestinal disorders (72, 73).