Neonatal vitamin D status and myopia in young adult men

PURPOSE: The prevalence of myopia is increasing worldwide, and modifiable risk factors are thus important to identify. Season of birth has been associated with later myopia risk. Neonatal vitamin D status is highly dependent on season of birth due to maternal sun exposure late in gestation. We hypothesize that prenatal exposure to low levels of vitamin D can interfere with visual development in term-born infants and that this might contribute to adult visual dysfunction. The aim of this study was thus to compare neonatal vitamin D levels from stored dried blood spots taken shortly after birth among young term-born men with myopia (cases) and random controls with emmetropia. METHODS: In this case-control study, we analysed neonatal 25(OH)D3 levels of 457 myopic male cases and 1280 emmetropic male controls assessed for myopia at the mandatory Danish conscript examination. Data were analysed using logistic regression analysis and results presented as crude and adjusted for potential confounders namely maternal age, maternal ethnicity, maternal and paternal education and season of birth. RESULTS: We did not observe a seasonal variation in myopia risk, neither did we observe increased odds of myopia in relation to low neonatal 25(OH)D3 levels. CONCLUSION: The rapid increase in myopia does not seem related to neonatal vitamin D status.