Abstract
BACKGROUND: Vitamin deficiencies are linked to various eye diseases, and the influence of vitamin D on cataract formation has been noted in prior research. However, detailed investigations into the causal relationship between 25-(OH)D status and cataract development remain scarce. AIM: To explore a possible causal link between cataracts and vitamin D. METHODS: In this study, we explored the causal link between 25-(OH)D levels and cataract development using Mendelian randomization. Our analytical approach included inverse-variance weighting (IVW), MR-Egger, weighted median, simple mode, and weighted mode methods. The primary analyses utilized IVW with random effects, supplemented by sensitivity and heterogeneity tests using both IVW and MR-Egger. MR-Egger was also applied for pleiotropy testing. Additionally, a leave-one-out analysis helped identify potentially impactful single-nucleotide polymorphisms. RESULTS: The analysis revealed a positive association between 25-(OH)D levels and the risk of developing cataracts (OR = 1.11, 95%CI: 1.00-1.22; P = 0.032). The heterogeneity test revealed that our IVW analysis exhibited minimal heterogeneity (P > 0.05), and the pleiotropy test findings confirmed the absence of pleiotropy within our IVW analysis (P > 0.05). Furthermore, a search of the human genotype-phenotype association database failed to identify any potentially relevant risk-factor single nucleotide polymorphisms. CONCLUSION: There is a potential causal link between 25-(OH)D levels and the development of cataracts, suggesting that greater 25-(OH)D levels may be a contributing risk factor for cataract formation. Further experimental research is required to confirm these findings.