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% CIs 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; I2 = 80%; Pheterogeneity = 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; I2 = 89%; Pheterogeneity = 0.01).

CONCLUSION: There is a statistically significant association between vitamin D deficiency and DR.