Relation between vitamin D deficiency and diabetic maculopathy

Vitamin D deficiency has been linked to DR progression, its specific role in diabetic maculopathy remains underexplored. This study aimed to evaluate the relationship between serum vitamin D levels and diabetic maculopathy. In this cross-sectional study, 68 patients with diabetic macular edema (DME) underwent comprehensive ophthalmic examinations, including OCTA to assess superficial and deep vascular density and foveal avascular zone (FAZ), alongside measurement of serum vitamin D levels. Patients with renal impairment, granulomatous diseases, or vitamin D supplementation were excluded. Of the 68 patients (54.4% female, 45.6% male; mean age 58 ± 7 years), vitamin D levels showed significant positive correlations with superficial vascular density in foveal (r = 0.711, P < 0.001), parafoveal (r = 0.852, P < 0.001), and perifoveal zones (r = 0.832, P < 0.001), and with deep vascular density in foveal (r = 0.868, P < 0.001), parafoveal (r = 0.790, P < 0.001), and perifoveal zones (r = 0.645, P < 0.001). Negative correlations were observed with FAZ in superficial (r = - 0.806, P < 0.001) and deep layers (r = - 0.801, P < 0.001). Multivariate linear regression, controlling for age, gender, and diabetes duration, confirmed vitamin D as a significant predictor of superficial and deep vascular density and FAZ parameters. Diabetic macular ischemia is closely linked to vitamin D deficiency, as shown by reduced vascular density and enlarged FAZ. These findings suggest that vitamin D may help prevent retinal microvascular damage in diabetic retinopathy.