Inverse Relationship Between High Blood 25-Hydroxyvitamin D and Late Stage of Age-Related Macular Degeneration in a Representative Korean Population

PURPOSE. To investigate the association of 25-hydroxyvitamin D with AMD. METHODS. A population-based, cross-sectional study using a nationwide, systemic-stratified, multistage-clustered sampling method involved a total of 17,045 subjects older than 40 years who participated in the Korean National Health and Nutrition Examination Survey 2008 to 2012. All participants underwent standardized interviews, evaluation of blood 25-hydroxyvitamin D levels, and comprehensive ophthalmic examinations. A 45 degrees digital fundus photograph of both eyes was taken under physiologic mydriasis. All fundus photographs were graded using the international classification and grading system. RESULTS. Blood 25-hydroxyvitamin D levels were 17.5 ng/mL in women and 20.0 ng/mL in men. After adjusting for potential confounders including age, sex, smoking status, hypertension, heart problems, stroke, and sunlight-exposure time, the odds ratio (OR) for late AMD significantly decreased in the highest blood 25-hydroxyvitamin D quintile (OR, 0.32; 95% confidence interval [CI], 0.12-0.81; P for trend = 0.018) compared with the lowest quintile in men, but not in women. Early AMD was not associated with blood 25-hydroxyvitamin D levels in either sex. CONCLUSIONS. High level of blood 25-hydroxyvitamin D was inversely associated with late AMD in men but not women. Considering antiangiogenic and antifibrotic action of vitamin D, association between two variables warrants further studies.