The impact of vitamin D supplementation on dry eye disease and lens clarity in vitamin d deficient university students
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Abstract
Background: To evaluate how well taking oral vitamin D helps reduce symptoms of dry eye disease (DED), increase vitamin D levels in the blood, and improve other eye conditions (like lens clarity and vision) in university students who are low in vitamin D.
Methods: In this pre-post interventional study, 41 vitamin D-deficient university students with dry eye disease (confirmed by OSDI score) received 50,000 IU of oral vitamin D weekly for eight weeks. The outcome measures comprised OSDI scores, serum vitamin D levels, lens clarity, and refractive error, evaluated at baseline and following the intervention. The Wilcoxon Signed Ranks Test and Spearman's correlation were used to do the statistical analysis.
Results: After treatment, there was a significant decrease in OSDI scores (from 33.82 ± 8.47 to 22.68 ± 8.25; Z = -5.59, p < 0.001) and a notable increase in serum vitamin D levels (from 12.70 ± 3.68 ng/mL to 33.09 ± 7.24 ng/mL). Furthermore, a Spearman's correlation coefficient indicated a significant, moderate-to-strong relationship between changes in vitamin D levels and changes in OSDI scores (r = -0.68, p < 0.001). According to the coefficient of determination (R2 = 0.464), the increase in vitamin D levels accounts for approximately 46.4% of the variation in the relief of dry eye symptoms. Additionally, nearly two-thirds of participants (65.85%) met the MCID criteria for clinical improvement. There was also a statistically significant improvement in lens clarity, with values changing from 2.05 ± 0.89 to a post-intervention mean of 1.46 ± 0.78 (where clear lens = 1, mildly cloudy = 2, and moderately cloudy = 3). This change was confirmed by the Wilcoxon signed-rank test (Z = -3.169, p = 0.002).
Conclusion: High-dose vitamin D supplementation effectively addresses vitamin D deficiency, leading to statistically and clinically significant improvements in dry eye symptoms and lens clarity. The inverse relationship between higher serum vitamin D levels and lower OSDI scores suggests that vitamin D may help treat dry eye disease (DED).
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