title: Serum 25-Hydroxyvitamin D Levels and Dry Eye Syndrome: Differential Effects of Vitamin D on Ocular Diseases.
abstract: OBJECTIVE
  To investigate associations between serum 25-hydroxyvitamin D levels and dry eye syndrome (DES), and to evaluate the differential effect of vitamin D on ocular diseases including age-related macular disease (AMD), diabetic retinopathy (DR), cataract, and DES.
  
  
  METHODS
  A total of 16,396 participants aged >19 years were randomly selected from the Korean National Health and Nutrition Examination Survey. All participants participated in standardized interviews, blood 25-hydroxyvitamin D level evaluations, and comprehensive ophthalmic examinations. DES was defined by a history of clinical diagnosis of dry eyes by a physician. The association between vitamin D and DES was compared to the associations between vitamin D and AMD, DR, cataract, and DES from our previous studies.
  
  
  RESULTS
  The odds of DES non-significantly decreased as the quintiles of serum 25-hydroxyvitamin D levels increased (quintile 5 versus 1, OR = 0.85, 95%CI: 0.55-1.30, P for trend = 0.076) after adjusting for potential confounders including age, sex, hypertension, diabetes, smoking status, and sunlight exposure times. The relative odds of DES (OR = 0.70, 95% CI: 0.30-1.64) and cataract (OR = 0.76, 95% CI: 0.59-0.99) were relatively high, while those of DR (OR = 0.37, 95% CI: 0.18-0.76) and late AMD (OR = 0.32, 95% CI: 0.12-0.81) were lower in men.
  
  
  CONCLUSIONS
  The present study does not support an association between serum 25-hydroxyvitamin D levels and DES. The preventive effect of serum 25-hydroxyvitamin D may be more effective for DR and late AMD than it is for cataract and DES.
authors.affiliation: Department of Ophthalmology and Visual Science, College of Medicine, Catholic University of Korea, Suwon, Korea.|Department of Epidemiology and Biostatistics, Harvard T.H. Chan School of Public Health, Boston, Massachusetts, United States of America.
authors.forename: Donghyun
authors.initials: D
authors.lastname: Jee
authors.affiliation: Department of Ophthalmology and Visual Science, Daejeon St. Mary's Hospital, College of Medicine, Catholic University of Korea, Daejeon, Korea.
authors.forename: Seungbum
authors.initials: S
authors.lastname: Kang
authors.affiliation: Department of Nutrition and Epidemiology, Harvard T.H. Chan School of Public Health, Boston, Massachusetts, United States of America.
authors.forename: Changzheng
authors.initials: C
authors.lastname: Yuan
authors.affiliation: Channing Division of Network Medicine, Brigham and Women's Hospital and Harvard Medical School, Boston, Massachusetts, United States of America.|Department of Dermatology, The Warren Alpert Medical School of Brown University, Providence, Rhode Island, United States of America.
authors.forename: Eunyoung
authors.initials: E
authors.lastname: Cho
authors.affiliation: Department of Ophthalmology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Massachusetts, United States of America.
authors.forename: Jorge G
authors.initials: JG
authors.lastname: Arroyo
mesh_terms: D000328:Adult; D003430:Cross-Sectional Studies; D003930:Diabetic Retinopathy / Q000097:blood / Q000453:epidemiology; D015352:Dry Eye Syndromes / Q000097:blood* / Q000453:epidemiology / Q000209:etiology; D005260:Female; D006801:Humans; D008268:Macular Degeneration / Q000097:blood / Q000453:epidemiology; D008297:Male; D008875:Middle Aged; D016017:Odds Ratio; D015995:Prevalence; D062486:Public Health Surveillance; D056910:Republic of Korea / Q000453:epidemiology; D012307:Risk Factors; D012737:Sex Factors; D014807:Vitamin D / Q000031:analogs & derivatives* / Q000097:blood
chemical_list: D014807:Vitamin D; C104450:25-hydroxyvitamin D