Serum concentrations of 25-hydroxyvitamin D and different subtypes of age-related cataract; a case-control study

Introduction: Age-related cataract (ARC) is the principal causes of low vision and also the most prevalent type of cataract among the elderly population, particularly women. Objectives: lo evaluate the association between serum concentration of vitamin D and risk of different subtypes of senile cataract. Patients and Methods: A total of 200 controls and 1241 patients with newly recognized ARC attending the ophthalmology ward of a major teaching hospital in Urmia, Iran, were included in this investigation. All included subjects aged 40 to 85 years. Cataracts were classified as pure nuclear cataract (NC) (n=216), pure cortical cataract (CC) (n=336), pure posterior sub-capsular cataract (PSC) (n=140) and mixed cataracts (549). Serum concentration of 25-hydroxyvitamin D was obtained from blood samples. All participants were administered by a questionnaires to collect data on demographic variables and risk factors. Results: On multivariate analysis, a marked negative association (P < 0.05) was found between vitamin D serum levels and the risk of NC (OR = 0.20; 95% CI: 0.09-0.75) or CC (OR = 0.25; 95% CI: 0.12-0.96) in females only. Other significant predictors of pure NC in women were higher education (OR = 0.51) and serum calcium levels (OR = 0.35). Apart from serum concentrations of vitamin D, postmenopausal status (OR = 2.26) was the other predisposing factor for pure cortical opacity in women. Conclusion: Our finding does not endorse a role for vitamin D in cataractogenesis among men. In women, however, serum levels of 25(OH)D were only inversely associated with the risk of NC and CC and not with PSC or mixed cataract. Providing sufficient vitamin D is possibly helpful in preventing senile cataract formation in females.