Vitamin D deficiency is associated with an increased risk of incident retinal vein occlusion in a propensity score-matched cohort study

Vitamin D deficiency (VDD) has been implicated in vascular dysfunction, but its relationship with incident retinal vein occlusion (RVO) remains uncertain. We conducted a retrospective propensity score–matched cohort study using the TriNetX Global Collaborative Network. Adults aged ≥ 50 years with two serum 25-hydroxyvitamin D measurements recorded between 2010 and 2023 were classified as having VDD (< 20 ng/mL) or sufficient vitamin D status (≥ 30 ng/mL). The primary outcome was incident RVO over 12 years after a 2-year landmark period; secondary outcomes included central RVO, branch RVO, and all-cause blindness. After 1:1 matching, each cohort included 227,216 patients. VDD was associated with higher risks of incident RVO (hazard ratio [HR] 1.58, 95% confidence interval [CI] 1.28–1.96; p < 0.001), central RVO (HR 1.53, 95% CI 1.14–2.05), branch RVO (HR 1.65, 95% CI 1.24–2.21), and all-cause blindness (HR 1.85, 95% CI 1.56–2.20). Estimates were comparable in the vitamin D insufficiency analysis and remained consistent across sensitivity and subgroup analyses. VDD was therefore associated with an elevated long-term risk of retinal vascular events, although causality cannot be inferred from this observational study.