Association Between Calcium Supplement Use and Cognitive Impairment in Ageing Women: A Longitudinal Analysis

OBJECTIVE: Calcium supplementation is widely used in older adults, but its long-term effects on cognitive function remain unclear. This study assessed the association between pharmacological calcium supplementation and cognitive decline over 7 years in cognitively healthy older women. METHODS: This prospective cohort study included 227 women (mean age 79.9 ± 3.6 years) from the Toulouse centre of the EPIDOS study. Cognitive function was assessed using the Short Portable Mental Status Questionnaire (SPMSQ) at baseline and after 7 years. Cognitive decline was defined as a decrease of at least one point in SPMSQ score. Calcium supplement use at baseline was recorded. Multivariable logistic regression was used to evaluate the association between supplementation and cognitive decline, adjusted for age, obesity, physical activity, instrumental activities of daily living (iADL) score, education level, dietary calcium and vitamin D intake, number of comorbidities and selected chronic conditions. RESULTS: Cognitive decline occurred in 26% of participants. Calcium supplementation was reported by 12% of patients and was independently associated with an increased risk of cognitive decline (OR = 3.64; 95% CI: 1.47-9.01; p = 0.005). Obesity and comorbidity burden were also significant risk factors. CONCLUSIONS: Calcium supplementation was associated with a threefold increased risk of cognitive decline in older women over a 7-year follow-up. These results suggest caution in prescribing calcium supplements and underscore the need for further research on their neurological safety in ageing populations.