title: Association between serum 25(OH) vitamin D, incident liver cancer and chronic liver disease mortality in the Linxian Nutrition Intervention Trials: a nested case-control study.
abstract: BACKGROUND
  Although vitamin D deficiency has been noted in cross-sectional studies of chronic liver disease and laboratory studies suggest possible benefits of vitamin D in preventing liver cancer, little epidemiologic data are available.
  
  
  METHODS
  We performed a nested case-control study in the Linxian Nutrition Intervention Trials on participants developing incident liver cancer or dying from chronic liver disease over 22 years of follow-up. Baseline serum 25(OH) vitamin D was measured for 226 incident liver cancer cases, 282 chronic liver disease deaths and 1063 age-, sex- and trial-matched controls. Unconditional logistical regression models were used to estimate odds ratios (ORs) and 95% confidence intervals (CIs).
  
  
  RESULTS
  The median serum vitamin D level in controls was low (20 nmol l(-1)). Compared with the lowest quartile, subjects in the fourth quartile had lower risk of chronic liver disease death (OR=0.34, 95% CI=0.21-0.55). For liver cancer incidence, risk estimates were below one, but were not statistically significant. Associations, however, were significant among participants with higher serum calcium levels (Q4 vs Q1, OR=0.43, 95% CI=0.21-0.89). Results for chronic liver disease did not vary by serum calcium level.
  
  
  CONCLUSIONS
  In a low vitamin D population, higher serum 25(OH) vitamin D concentrations were associated with significantly lower risk of chronic liver disease deaths, and among those with higher serum calcium, incident liver cancer. Our results suggest a possible protective role for vitamin D in these diseases.
authors.affiliation: 1] Department of Cancer Epidemiology, Cancer Institute/Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100021, China [2] Nutritional Epidemiology Branch, Division of Cancer Epidemiology and Genetics, National Cancer Institute, Rockville, MD 20850, USA.
authors.forename: J-B
authors.initials: JB
authors.lastname: Wang
authors.forename: C C
authors.initials: CC
authors.lastname: Abnet
authors.forename: W
authors.initials: W
authors.lastname: Chen
authors.forename: S M
authors.initials: SM
authors.lastname: Dawsey
authors.forename: J-H
authors.initials: JH
authors.lastname: Fan
authors.forename: L-Y
authors.initials: LY
authors.lastname: Yin
authors.forename: J
authors.initials: J
authors.lastname: Yin
authors.forename: J M
authors.initials: JM
authors.lastname: Major
authors.forename: P R
authors.initials: PR
authors.lastname: Taylor
authors.forename: Y-L
authors.initials: YL
authors.lastname: Qiao
authors.forename: N D
authors.initials: ND
authors.lastname: Freedman
mesh_terms: D000328:Adult; D000368:Aged; D002118:Calcium / Q000097:blood; D016022:Case-Control Studies; D002681:China; D005260:Female; D006801:Humans; D015994:Incidence; D008107:Liver Diseases / Q000097:blood / Q000453:epidemiology* / Q000401:mortality; D008113:Liver Neoplasms / Q000097:blood / Q000453:epidemiology* / Q000401:mortality; D008297:Male; D008875:Middle Aged; D009752:Nutritional Status; D012306:Risk; D012307:Risk Factors; D013472:Sunlight; D014807:Vitamin D / Q000031:analogs & derivatives* / Q000097:blood; D014808:Vitamin D Deficiency / Q000097:blood*
chemical_list: D014807:Vitamin D; C104450:25-hydroxyvitamin D; D002118:Calcium