The Association Between Vitamin D Deficiency and Nondiabetic Retinopathy in the American Population: National Health and Nutrition Examination Survey 2005–2008

<b>Objectives:</b> Retinopathy is a vascular endothelial injury disease that can occur in individuals without diabetes. The prevalence rates of nondiabetic retinopathy (NDR) vary from 6% to 13.6% among individuals. Vitamin D deficiency (VDD) is common worldwide, and studies indicate that the overall prevalence rate of VDD in US adults is 41.6%. Ample evidence indicates an inconsistent relationship between VDD and diabetic retinopathy, but the association between VDD and NDR remains limited. <b>Design:</b> We conducted a population-based, cross-sectional study. <b>Settings:</b> The study was conducted using data from the National Health and Nutrition Examination Survey 2005-2008. <b>Participants:</b> A total of 4076 adults (52.71% female) with a mean age of 55.79 ± 11.72 years were included. <b>Primary and Secondary Outcomes:</b> The primary outcome was the association between vitamin D and NDR, while there was no secondary outcome. <b>Results:</b> Retinopathy was detected in 309 nondiabetic subjects (7.6%), while VDD was detected in 19.36% of the NDR participants. In the univariate analysis, significant associations were found between systolic blood pressure (odds ratio [OR]: 1.02; 95% confidence interval (CI): 1.00, 1.04; <i>p</i> = 0.0227), physical activity group (OR: 0.63; 95% CI: 0.51, 0.78; <i>p</i> = 0.0001), and retinopathy in the nondiabetic participants. Logistic regression analysis revealed that after adjusting for other confounders, no statistically significant association between vitamin D concentration and NDR severity was found (OR: 1.02; 95% CI: 0.97; 1.06; <i>p</i> = 0.9024). Similarly, smooth curve fitting could not find any trend between the two. Moreover, these results were consistent with the results of taking vitamin D (quartile) as a categorical variable (<i>p</i> for trend was 0.8401). <b>Conclusion:</b> In the present study, serum vitamin D concentrations within the observed range were not significantly associated with NDR risk in the nondiabetic US population, indicating that vitamin D status is unlikely to be a primary determinant of subclinical microvascular pathology in nondiabetic adults.