CALCIUM supplements do not raise the risk of dementia in older women, according to a large, long-term randomised study. Over 14.5 years, researchers followed 1,460 women taking either calcium monotherapy or placebo, finding no difference in cognitive outcomes, even when accounting for genetics, lifestyle, and diet.
Calcium Supplements and Dementia: Safety Reassurance
Dementia is a leading concern for ageing populations, and previous studies raised fears that calcium pills might increase cognitive decline risk. However, this robust analysis compared five years of calcium supplementation with placebo and tracked health outcomes extensively. After nearly 15 years, there was no notable difference in rates of dementia-related hospitalisations or deaths, regardless of compliance or other risk factors.
Study Design: Long-Term Evidence
The Perth Longitudinal Study of Aging Women involved randomising community-dwelling women aged 70 and above to either daily calcium (730 women) or placebo (730 women) for five years, with extended follow-up for 9.5 more years. Dementia events were tracked using linked hospital and death records, and statistical analyses, including Kaplan-Meier survival curves and Cox regression, showed no increased hazard of dementia with calcium use. Adjustments for supplement compliance, diet, and genetic risk made no difference to the findings.
Outlook for Bone and Brain Health in Older Women
These findings provide strong reassurance for older women and healthcare providers: calcium supplementation does not increase dementia risk in the long term, despite previous concern. While benefits for bone health are well established, future trials should explore effects in men and younger women, and rigorously assess cognitive outcomes with calcium use.
Reference
Ghasemifard N et al. Calcium supplementation and the risk of dementia in the Perth Longitudinal Study of Aging Women: a post-hoc analysis of a randomised clinical trial for fracture prevention. The Lancet Regional Health–Western Pacific. 2025;DOI:10.1016/j.lanwpc.2025.101694.
