Policlinico Umberto I Hospital, Sapienza University of Rome, Viale Regina Elena, 324 00161-Rome, Italy.
Department of Public Health and Infectious Diseases, Sapienza University of Rome, Viale Regina Elena, 324 00161- Rome, Italy.
Mini Rev Med Chem. 2019;19(4):310-332. doi: 10.2174/1389557518666181025153712.
Nonalcoholic fatty liver disease (NAFLD), historically considered to be the hepatic component of the metabolic syndrome, is a spectrum of fat-associated liver conditions, in the absence of secondary causes, that may progress to nonalcoholic steatohepatitis (NASH), fibrosis, and cirrhosis. Disease progression is closely associated with body weight or fatness, dyslipidemia, insulin resistance, oxidative stress, and inflammation. Recently, vitamin D deficiency has been linked to the pathogenesis and severity of NAFLD because of vitamin D "pleiotropic" functions, with roles in immune modulation, cell differentiation and proliferation, and regulation of inflammation. Indeed, several studies have reported an association between vitamin D and NAFLD/NASH. However, other studies have failed to find an association. Therefore, we sought to critically review the current evidence on the association between vitamin D deficiency and NAFLD/NASH, and to analyze and discuss some key variables that may interfere with this evaluation, such as host-, environment-, and heritability-related factors regulating vitamin D synthesis and metabolism; definitions of deficient or optimal vitamin D status with respect to skeletal and nonskeletal outcomes including NAFLD/NASH; methods of measuring 25(OH)D; and methods of diagnosing NAFLD as well as quantifying adiposity, the cardinal link between vitamin D deficiency and NAFLD.
非酒精性脂肪性肝病（NAFLD），历史上被认为是代谢综合征的肝脏成分，是一系列与脂肪相关的肝脏疾病，在没有继发性原因的情况下，可能进展为非酒精性脂肪性肝炎（NASH）、纤维化和肝硬化。疾病进展与体重或肥胖、血脂异常、胰岛素抵抗、氧化应激和炎症密切相关。最近，由于维生素 D 的“多效性”功能，维生素 D 缺乏与 NAFLD 的发病机制和严重程度有关，其在免疫调节、细胞分化和增殖以及炎症调节中发挥作用。事实上，几项研究报告了维生素 D 与 NAFLD/NASH 之间的关联。然而，其他研究未能发现这种关联。因此，我们试图批判性地回顾目前关于维生素 D 缺乏与 NAFLD/NASH 之间关联的证据，并分析和讨论一些可能干扰这种评估的关键变量，例如调节维生素 D 合成和代谢的宿主、环境和遗传性因素；关于骨骼和非骨骼结局（包括 NAFLD/NASH）的维生素 D 缺乏或最佳状态的定义；25(OH)D 的测量方法；以及 NAFLD 的诊断方法以及肥胖程度的量化，肥胖是维生素 D 缺乏与 NAFLD 之间的主要联系。
