Association between serum 25-hydroxyvitamin D levels and myopia in general Korean adults

PURPOSE: We performed this study to determine the association between serum 25-hydroxyvitamin D [25(OH) D] level and myopia in adults. METHODS: A total of 25,199 subjects aged ≥20 years were included from the National Health and Nutrition Examination Survey 2008–2012. Blood 25(OH)D levels were evaluated from blood samples. Refractive error was measured without cycloplegia. Myopia and high myopia were defined as ≥-0.50 diopters (D) and ≥-6.0 D, respectively. Other covariates such as education, physical activity, and economic status were obtained from interviews. RESULTS: Linear regression analysis showed that as 25(OH) D level increased by 1 ng/mL, myopic refractive error significantly decreased by 0.01 D (P < 0.001) after adjusting for potential confounders including sex, age, height, education level, economic status, physical activity, and sunlight exposure time. The odds ratios for myopia was 0.75 (95% Confidence interval [CI]; 0.67–0.84, P < 0.001) in the highest 25(OH) D quintile compared to the lowest quintile. The odds ratios for high myopia was 0.63 (95% CI; 0.47–0.85, P < 0.001) in the highest 25(OH)D quintile compared to the lowest quintile. CONCLUSION: Serum 25(OH)D level was inversely associated with myopia in Korean adults.