Open-angle glaucoma (OAG) is one of the major chronic diseases involving the optic nerve. However, little is known about the association between vitamin D and OAG. The present study was conducted to test the hypothesis that lower vitamin D status is associated with greater prevalence of OAG.

Cross-sectional study. Multivariable logistic regression was performed to examine the relationship between serum 25-hydroxyvitamin D (25(OH)D) and OAG after adjusting for traditional potential confounders. OAG was defined by the criteria of the International Society for Geographical and Epidemiological Ophthalmology.

The Fifth Korean National Health and Nutrition Examination Survey conducted in 2010–2011.

Six thousand and ninety-four adult participants randomly selected from 192 surveys in 131 locations in South Korea.

Multivariable-adjusted odds ratios of OAG across quintiles of decreasing 25(OH)D were 1·26, 1·00 (reference), 1·31, 1·36 and 1·69 (P for quadratic trend <0·01). The odds ratio for the lowest 25(OH)D quintile was significantly higher than that for the second quintile (P < 0·01). In addition, we discovered that the predictors for worsening of OAG, such as intraocular pressure or vertical and horizontal cup-to-disc ratios, had a significant relationship with 25(OH)D level.

There was a reverse J-shaped association between 25(OH)D levels and the risk of OAG, with significantly elevated risk at lower 25(OH)D. The findings of this research suggest that vitamin D deficiency should be considered as a potential risk factor for the development of OAG. To our knowledge, the present study is the first one that shows an association between vitamin D status and OAG.