Relationship between vitamin D deficiency and diabetic retinopathy: a meta-analysis

Objective: The purpose of this study was to evaluate the evidence for an association between diabetic retinopathy (DR) and vitamin D deficiency. Design: Meta-analysis. Methods: We included 14 observational studies with 10 007 participants who had undergone assessment for both DR and vitamin D deficiency. Pooled odds ratios (ORs) and 95% Cls were calculated using a random-effect, Mantel Haenszel analysis. Results: There was a statistically significant association between DR and vitamin D deficiency with an overall pooled OR of 1.27 (95% CI, 1.17-1.37; P = 0.001; t- 80%; P heterogeneity 0.01). There was also a statistically significant lower serum vitamin D level in patient subgroups with DR versus control groups, with an overall mean difference of 1.32 ng/mL (95% CI, 2.50 to 0.15; P = -0.001; beta = 89%; Pheteroge neity 0.01). Conclusion: There is a statistically significant association between vitamin D deficiency and DR.