VDR and obesity due to melanocortin 4 receptor deficiency: Since there are close links between VD/VDR and VD/AhR signaling with tissue barriers and epithelial integrity [8,40], this study compared the efficacies of different forms of VD with clinically relevant dosages on MLN CD4+ T cell polarization and their association with intestinal inflammation and injury in a critical condition of obesity complicated with sepsis.