Similar to what we observed in the dietary impact, the genetic ablation of the vitamin D receptor (VDR KO) resulted in reduced DEFA5 and MMP7 expression in the ileum, increased intestinal permeability, ileal dysbiosis, and hepatic steatosis, which collectively demonstrates a critical role for vitamin D signaling in maintaining intestinal integrity, eubiosis, and metabolic homeostasis. This evidence concerns the gene DEFA5 and fatty liver disease.