BUFFALO, NY¡ªA study of data collected form the Carotenoids in Age-Related Eye Disease Study (CAREDS) showed high serum vitamin D concentrations may protect against early age-related macular degeneration (AMD) in women under the age of 75. Researchers from the University of Buffalo published their findings in the April issue of Archives of Ophthalmology (129(4):481-489).
The study looked at the relationship between serum 25-hydroxyvitamin D (25[OH]D) concentrations (nmol/L) and the prevalence of early AMD in women. Researchers assessed AMD status using stereoscopic fundus photographs, taken from 2001 to 2004. Baseline serum samples obtained form 1994 to 1998 were available for 25(OH)D assays in 1,313 women with complete ocular and risk factor data. Odds ratios (ORs) and 95-percent confidence intervals (CIs) for early AMD (n = 241) of 1,287 without advanced disease were estimated with logistic regression and adjusted for age, smoking, iris pigmentation, family history of AMD, cardiovascular disease, diabetes, and hormone therapy use.
In multivariate models, no significant relationship was observed between early AMD and 25(OH)D (OR for quintile 5 vs. 1, 0.79; 95% CI, 0.50-1.24; P for trend = .47). A significant age interaction (P = .002) suggested selective mortality bias in women aged 75 years and older: serum 25(OH)D was associated with decreased odds of early AMD in women younger than 75 years (n = 968) and increased odds in women aged 75 years or older (n = 319) (OR for quintile 5 vs 1, 0.52; 95% CI, 0.29-0.91; P for trend = .02 and OR, 1.76; 95% CI, 0.77-4.13; P for trend = .05, respectively). After adjusting for body mass index (BMI) and recreational physical activity, researchers found predictors of 25(OH)D, attenuated the observed association in women younger than 75 years. Additionally, intake of vitamin D from foods and supplements among women younger than 75 years was related to decreased odds of early AMD in multivariate models, but no relationship was observed with self-reported time spent in direct sunlight.