New research from Edith Cowan University (ECU), Curtin University and the University of Western Australia has found no evidence that calcium supplements increase the long-term risk of dementia, easing earlier concerns about their possible impact on brain health in older women. The study helps clarify years of uncertainty surrounding calcium monotherapy, which is commonly used to support bone health in later life.
The investigation drew on data from a previous five-year clinical trial involving 1,460 older women who received either calcium supplements or a placebo. Over a follow-up period of more than 14 years, researchers found that taking calcium did not raise the likelihood of developing dementia. This finding reassures both patients and healthcare providers that calcium supplementation remains safe in the context of cognitive decline.
ECU PhD student Ms Negar Ghasemifard explained that calcium supplements are widely recommended to prevent or manage osteoporosis, a condition affecting roughly one in five women over the age of seventy. She noted that previous studies had raised concerns about a potential link between calcium and dementia risk. Still, these new results provide confidence in the continued use of calcium supplements for bone protection without fear of cognitive harm.
Senior Research Fellow Dr Marc Sim emphasised that the study’s strength lies in its design. By adjusting for supplement compliance, dietary intake, lifestyle factors, and genetic risk, the researchers confirmed that their findings remained consistent. Unlike earlier observational studies that could not rule out hidden confounding factors, this double-masked, placebo-controlled randomised clinical trial provided more reliable evidence.
Dr Sim added that the trial’s long duration and careful tracking of dosage and compliance strengthened the credibility of the results. With 730 participants receiving calcium and 730 receiving placebo over five years, followed by a median of 14.5 years of monitoring, the data indicated no significant link between calcium use and all-cause dementia risk in older women.
While the findings are encouraging, ECU’s Centre for Precision Health Director Professor Simon Laws cautioned that further research is needed to determine whether similar results would apply to other groups, such as men or younger women who begin supplementation earlier in life. He suggested that future trials should include detailed brain health assessments as primary outcomes to confirm the long-term cognitive safety of calcium supplements.
More information: Negar Ghasemifard 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. DOI: 10.1016/j.lanwpc.2025.101694
Journal information: The Lancet Provided by Edith Cowan University
