Vitamin D and Age-Related Macular Degeneration
Age-related macular degeneration (AMD) is the leading cause of vision loss in individuals aged 50 years and older and is estimated to affect as many as 11 million individuals in the United States. The purpose of this study was to examine the association between vitamin D and AMD disease progression. The life course epidemiology framework model was used to explore how vitamin D level as a risk factor may have an association to AMD disease through time. Data in the 2005–2008 National Health and Nutrition Examination Survey (NHANES) database were collected on vitamin D levels and identified stages of AMD level based on graded fundus eye exams from an available sample size of 5,604 participants. A quantitative cross-sectional study approach was used to address this gap in knowledge. A bivariate analysis was used to examine each independent variable (age, race/ethnicity, smoking status, and diabetes) to the dependent variable AMD from the 2005–2008 NHANES dataset. A multivariate logistic regression analysis was performed with AMD including each independent variable found to be significant. The findings from this study failed to suggest an association between vitamin D levels to AMD, with or without the covariates included in the model. There was not an association found between vitamin D level and presence of AMD. An association was found between age, smoking, and race to presence of AMD in each of the bivariate models. The findings from this study could be used for positive social change by encouraging medical and public health agencies to target screening programs at high-risk age, smoking, and race groups. There remains to be conflicting data in the literature. This study adds to the body of literature suggesting that higher levels of vitamin D are not necessarily beneficial as they pertains to AMD.