title: Low serum vitamin D is associated with axial length and risk of myopia in young children.
abstract: The aim of the study was to investigate the relationship between serum 25(OH)D levels and axial length (AL) and myopia in 6-year-old children. A total of 2666 children aged 6 years participating in the birth-cohort study Generation R underwent a stepwise eye examination. First, presenting visual acuity (VA) and AL were performed. Second, automated cycloplegic refraction was measured if LogMAR VA > 0.1. Serum 25-hydroxyvitamin D [25(OH)D] was determined from blood using liquid chromatography/tandem mass spectrometry. Vitamin D related SNPs were determined with a SNP array; outdoor exposure was assessed by questionnaire. The relationships between 25(OH)D and AL or myopia were investigated using linear and logistic regression analysis. Average 25(OH)D concentration was 68.8 nmol/L (SD ± 27.5; range 4-211); average AL 22.35 mm (SD ± 0.7; range 19.2-25.3); and prevalence of myopia 2.3 % (n = 62). After adjustment for covariates, 25(OH)D concentration (per 25 nmol/L) was inversely associated with AL (β -0.043; P < 0.01), and after additional adjusting for time spent outdoors (β -0.038; P < 0.01). Associations were not different between European and non-European children (β -0.037 and β -0.039 respectively). Risk of myopia (per 25 nmol/L) was OR 0.65 (95 % CI 0.46-0.92). None of the 25(OH)D related SNPs showed an association with AL or myopia. Lower 25(OH)D concentration in serum was associated with longer AL and a higher risk of myopia in these young children. This effect appeared independent of outdoor exposure and may suggest a more direct role for 25(OH)D in myopia pathogenesis.
authors.affiliation: Department of Ophthalmology, Erasmus Medical Center, NA2808, PO Box 5201, 3008 AE, Rotterdam, The Netherlands.|Department of Epidemiology, Erasmus Medical Center, Rotterdam, The Netherlands.
authors.forename: J Willem L
authors.initials: JW
authors.lastname: Tideman
authors.affiliation: Department of Ophthalmology, Erasmus Medical Center, NA2808, PO Box 5201, 3008 AE, Rotterdam, The Netherlands.|Department of Orthoptics and Optometry, Faculty of Health, University of Applied Sciences, Utrecht, The Netherlands.
authors.forename: Jan Roelof
authors.initials: JR
authors.lastname: Polling
authors.affiliation: Department of Epidemiology, Erasmus Medical Center, Rotterdam, The Netherlands.
authors.forename: Trudy
authors.initials: T
authors.lastname: Voortman
authors.affiliation: Department of Epidemiology, Erasmus Medical Center, Rotterdam, The Netherlands.|Department of Paediatrics, Erasmus Medical Center, Rotterdam, The Netherlands.
authors.forename: Vincent W V
authors.initials: VW
authors.lastname: Jaddoe
authors.affiliation: Department of Epidemiology, Erasmus Medical Center, Rotterdam, The Netherlands.|Department of Internal Medicine, Erasmus Medical Center, Rotterdam, The Netherlands.
authors.forename: André G
authors.initials: AG
authors.lastname: Uitterlinden
authors.affiliation: Department of Epidemiology, Erasmus Medical Center, Rotterdam, The Netherlands.
authors.forename: Albert
authors.initials: A
authors.lastname: Hofman
authors.affiliation: Department of Ophthalmology, Erasmus Medical Center, NA2808, PO Box 5201, 3008 AE, Rotterdam, The Netherlands.
authors.forename: Johannes R
authors.initials: JR
authors.lastname: Vingerling
authors.affiliation: Department of Epidemiology, Erasmus Medical Center, Rotterdam, The Netherlands.
authors.forename: Oscar H
authors.initials: OH
authors.lastname: Franco
authors.affiliation: Department of Ophthalmology, Erasmus Medical Center, NA2808, PO Box 5201, 3008 AE, Rotterdam, The Netherlands. c.c.w.klaver@erasmusmc.nl.|Department of Epidemiology, Erasmus Medical Center, Rotterdam, The Netherlands. c.c.w.klaver@erasmusmc.nl.
authors.forename: Caroline C W
authors.initials: CC
authors.lastname: Klaver
mesh_terms: D058452:Axial Length, Eye; D002648:Child; D015331:Cohort Studies; D004777:Environment; D015444:Exercise; D005260:Female; D006801:Humans; D007899:Leisure Activities; D008019:Life Style; D008297:Male; D009216:Myopia / Q000097:blood / Q000150:complications / Q000453:epidemiology*; D009426:Netherlands / Q000453:epidemiology; D011159:Population Surveillance; D015995:Prevalence; D014807:Vitamin D / Q000031:analogs & derivatives* / Q000097:blood; D014808:Vitamin D Deficiency / Q000097:blood / Q000453:epidemiology*; D014815:Vitamins / Q000097:blood*
chemical_list: D014815:Vitamins; D014807:Vitamin D; C104450:25-hydroxyvitamin D
keywords: Axial length; Children; Myopia; Vitamin D