title: Vitamin E and risk of age-related cataract: a meta-analysis.
abstract: OBJECTIVE
  We conducted a meta-analysis to evaluate the relationship between vitamin E and age-related cataract (ARC).
  
  
  METHODS
  The fixed- or random-effect model was selected based on heterogeneity. Meta-regression was used to explore potential sources of between-study heterogeneity. Publication bias was evaluated using Begg's test. The dose-response relationship was assessed by a restricted cubic spline model.
  
  
  METHODS
  Relevant studies were identified by a search of PubMed and the Cochrane Library to May 2014, without language restrictions.
  
  
  METHODS
  Studies involved samples of people of all ages.
  
  
  RESULTS
  Dietary vitamin E intake, dietary and supplemental vitamin E intake, and high serum tocopherol levels were significantly associated with decreased risk of ARC, the pooled relative risk was 0·73 (95% CI 0·58, 0·92), 0·86 (95% CI 0·75, 0·99) and 0·77 (95% CI 0·66, 0·91), respectively. Supplemental vitamin E intake was non-significantly associated with ARC risk (relative risk=0·92; 95% CI 0·78, 1·07). The findings from dose-response analysis showed evidence of a non-linear association between dietary vitamin E intake and ARC. The risk of ARC decreased with dietary vitamin E intake from 7 mg/d (relative risk=0·94; 95% CI 0·90, 0·97).
  
  
  CONCLUSIONS
  The findings of the meta-analysis indicated that dietary vitamin E intake, dietary and supplemental vitamin E intake, and high level of serum tocopherol might be significantly associated with reduced ARC risk.
authors.affiliation: Department of Epidemiology and Health Statistics,Qingdao University Medical College,No. 38 Dengzhou Road,Qingdao 266021,People's Republic of China.
authors.forename: Yufei
authors.initials: Y
authors.lastname: Zhang
authors.affiliation: Department of Epidemiology and Health Statistics,Qingdao University Medical College,No. 38 Dengzhou Road,Qingdao 266021,People's Republic of China.
authors.forename: Wenjie
authors.initials: W
authors.lastname: Jiang
authors.affiliation: Department of Epidemiology and Health Statistics,Qingdao University Medical College,No. 38 Dengzhou Road,Qingdao 266021,People's Republic of China.
authors.forename: Zhutian
authors.initials: Z
authors.lastname: Xie
authors.affiliation: Department of Epidemiology and Health Statistics,Qingdao University Medical College,No. 38 Dengzhou Road,Qingdao 266021,People's Republic of China.
authors.forename: Wenlong
authors.initials: W
authors.lastname: Wu
authors.affiliation: Department of Epidemiology and Health Statistics,Qingdao University Medical College,No. 38 Dengzhou Road,Qingdao 266021,People's Republic of China.
authors.forename: Dongfeng
authors.initials: D
authors.lastname: Zhang
mesh_terms: D000375:Aging; D000975:Antioxidants / Q000627:therapeutic use*; D002386:Cataract / Q000097:blood / Q000517:prevention & control*; D004032:Diet; D019587:Dietary Supplements; D006801:Humans; D024505:Tocopherols / Q000097:blood; D014810:Vitamin E / Q000097:blood / Q000627:therapeutic use*; D014815:Vitamins / Q000627:therapeutic use*
chemical_list: D000975:Antioxidants; D014815:Vitamins; D014810:Vitamin E; D024505:Tocopherols
keywords: Age-related cataract; Meta-analysis; Serum tocopherol; Vitamin E