The Relationship Between Serum 25-Hydroxyvitamin D Levels and Nuclear Cataract in the Carotenoid Age-Related Eye Study (CAREDS), an Ancillary Study of the Women's Health Initiative

Cataracts are the most commonly diagnosed age-related eye disease in the United States, affecting an estimated 31% of individuals between the ages of 65 and 74 and 53% of individuals 75 years and older.1 Nuclear cataracts are the most common subtype in Americans.2 The major nonmodifiable risk factors are older age and brown iris color.3–6 Modifiable risk factors include lifestyles that can increase inflammation and oxidative stress: smoking,7–12 alcohol use,8,13–15 obesity,16–20 dietary patterns associated with low levels of micronutrients and phytochemicals,21 and low levels of physical activity.22,23 Pathophysiologically, nuclear cataract has been linked to intraocular and systemic inflammation24,25 and diseases with strong inflammatory components.3,4,26,27 Vitamin D has been suggested to have anti-inflammatory properties.28,29 Adequate vitamin D status may therefore be protective against nuclear cataract. However, no previous studies have directly evaluated relationships between serum biomarkers of vitamin D status and nuclear cataract. Our primary purpose was to investigate the association between serum 25-hydroxyvitamin D (25[OH]D) levels and nuclear cataract prevalence in postmenopausal women ages 50 to 79 residing in the northern United States using data from the Carotenoids in Age-Related Eye Disease Study (CAREDS). Our secondary aim was to evaluate to what extent serum C-reactive protein (CRP) levels, a marker of systemic inflammation, explained the potential association.