FIGURE 4.

Vitamin and NAFLD. Both vitamin E and vitamin D contribute to the regression of NAFLD. VE can induce the expression of adiponectin by activation of PPAR, enhancing insulin sensitivity consequently. Moreover, VE can inhibit lipogenesis and gluconeogenesis through the Nrf2/CES1 pathway, and alleviate oxidative stress via downregulation of iNOS and NADPH oxidase. It can lower the expression of TGF-β as well, which prevents liver fibrosis. Vitamin D supplementation can upregulate defensins associated with intestinal innate immunity, preventing IR consequently. VD can also suppress TLR4 on KCs and hepatocytes, which can downregulate NF-κB and is associated with inflammation. Activation of the VDRs on KCs and HSCs can improve insulin sensitivity and alleviate liver fibrosis, respectively. Abbreviations: CES1, carboxylesterase 1; iNOS, inducible nitric oxide synthase; Nrf2, nuclear factor erythroid 2-related factor 2; PPAR, peroxisome proliferation–activated receptor; TLR4, Toll-like receptor 4; VDR, vitamin D receptor.