title: The serum vitamin D level is inversely correlated with nonalcoholic fatty liver disease.
abstract: OBJECTIVE
  A low vitamin D level has been associated with metabolic syndrome and diabetes. However, an association between a low vitamin D level and nonalcoholic fatty liver disease (NAFLD) has not yet been definitively established. This study aimed to characterize the relationship between a vitamin D level and NAFLD in Korea.
  
  
  METHODS
  A cross-sectional study involving 6,055 health check-up subjects was conducted. NAFLD was diagnosed on the basis of typical ultrasonographic findings and a history of alcohol consumption.
  
  
  RESULTS
  The subjects were aged 51.7 ± 10.3 years (mean ± SD) and 54.7% were female. NAFLD showed a significant inverse correlation with the vitamin D level after adjusting for age and sex [odds ratio (OR)=0.85, 95% confidence interval (CI)=0.75-0.96]. The age- and sex-adjusted prevalence of NAFLD decreased steadily with increasing vitamin D level [OR=0.74, 95% CI=0.60-0.90, lowest quintile (≤14.4 ng/mL) vs highest quintile (≥28.9 ng/mL), p for trend <0.001]. Multivariate regression analysis after adjusting for other metabolic factors revealed that NAFLD showed a significant inverse correlation with both the vitamin D level (>20 ng/mL) [OR=0.86, 95% CI=0.75-0.99] and the quintiles of the vitamin D level in a dose-dependent manner (p for trend=0.001).
  
  
  CONCLUSIONS
  The serum level of vitamin D, even when within the normal range, was found to be inversely correlated with NAFLD in a dose-dependent manner. Vitamin D was found to be inversely correlated with NAFLD independent of known metabolic risk factors. These findings suggest that vitamin D exerts protective effects against NAFLD.
authors.affiliation: Department of Internal Medicine, Healthcare Research Institute, Gangnam Healthcare Center, Seoul National University Hospital, Seoul, Korea.
authors.forename: Goh Eun
authors.initials: GE
authors.lastname: Chung
authors.affiliation: Department of Internal Medicine, Healthcare Research Institute, Gangnam Healthcare Center, Seoul National University Hospital, Seoul, Korea.|Division of Gastroenterology and Hepatology, Stanford University School of Medicine, Stanford, California, USA.
authors.forename: Donghee
authors.initials: D
authors.lastname: Kim
authors.affiliation: Department of Internal Medicine, Healthcare Research Institute, Gangnam Healthcare Center, Seoul National University Hospital, Seoul, Korea.
authors.forename: Min-Sun
authors.initials: MS
authors.lastname: Kwak
authors.affiliation: Department of Internal Medicine, Healthcare Research Institute, Gangnam Healthcare Center, Seoul National University Hospital, Seoul, Korea.
authors.forename: Jong In
authors.initials: JI
authors.lastname: Yang
authors.affiliation: Department of Internal Medicine, Healthcare Research Institute, Gangnam Healthcare Center, Seoul National University Hospital, Seoul, Korea.
authors.forename: Jeong Yoon
authors.initials: JY
authors.lastname: Yim
authors.affiliation: Department of Internal Medicine, Healthcare Research Institute, Gangnam Healthcare Center, Seoul National University Hospital, Seoul, Korea.
authors.forename: Seon Hee
authors.initials: SH
authors.lastname: Lim
authors.affiliation: Pulmonary and Critical Care Consultant, Sheikh Khalifa Specialty Hospital, Ras AlKhaimah, UAE.
authors.forename: Mustafa
authors.initials: M
authors.lastname: Itani
mesh_terms: D000328:Adult; D000368:Aged; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D065626:Non-alcoholic Fatty Liver Disease / Q000097:blood / Q000175:diagnosis* / Q000000981:diagnostic imaging; D016017:Odds Ratio; D012044:Regression Analysis; D014463:Ultrasonography; D014807:Vitamin D / Q000097:blood*
chemical_list: D014807:Vitamin D
keywords: Fatty liver; Metabolic factor; Vitamin D