Calcium supplements do not appear to raise dementia risk. Long-term data support their safety for older women.
New findings from Edith Cowan University (ECU), Curtin University, and the University of Western Australia show no link between calcium supplementation alone and an increased long-term risk of dementia. The results ease earlier concerns that calcium might negatively affect brain health in older women.
The study drew on data from earlier research involving 1,460 women who received either calcium supplements or a placebo over a five-year period. Researchers found that calcium intake did not raise the likelihood of developing dementia later in life.
“Calcium supplements are often recommended to prevent or manage osteoporosis,” said ECU PhD student Ms Negar Ghasemifard.
Approximately 20 percent of women over 70 experience osteoporosis, and calcium is commonly advised as a preventive measure to reduce fracture risk.
Reassuring results for older women
“Previous research has raised concerns around the impacts that calcium supplements could have on cognitive health, particularly dementia. Results from our study provide reassurance to patients and clinicians regarding the safety of calcium supplements in the context of dementia risk for older women,” Ms Ghasemifard said.
ECU Senior Research Fellow Dr. Marc Sim noted that when the analysis was adjusted for supplement compliance, a range of lifestyle factors, including dietary calcium intake and genetic risk, the results remained unchanged.
“Previous research suggesting potential links between calcium supplement use and the risk for dementia was purely observational in nature. Our research, in comparison, consisted of a post-hoc analysis from a 5-year double-blind, placebo-controlled randomized clinical trial on calcium supplements to prevent fracture. Whilst our study is still epidemiology, its design does reduce the likelihood of unmeasured confounding.”
Strength of long-term data
“Some 730 older women were given calcium supplements over five years, and a further 730 were given a placebo. This study design offers more accurate data on dosage and duration, and we had a long follow-up period of 14.5 years, which strengthens our results,” Dr. Sim said.
Although the results help ease worries about calcium supplements and their connection to dementia in older women, especially those over 80, Professor Simon Laws, Director of ECU’s Centre for Precision Health, emphasized that additional studies are still needed.
“Whether this extrapolates to other demographics, such as men or even women commencing supplementation earlier in life, remains unknown. To confirm the current findings, particularly regarding brain health, and to address these population gaps, future clinical trials of calcium supplements, with or without vitamin D, would need to be undertaken. These should include specific and robust assessments of brain health as the primary outcome measures.”
Importance for clinical reassurance
Professor Blossom Stephan, a Dementia Australia Honorary Medical Advisor said the research highlighted a very important finding that provides reassurance to clinicians and patients about the long-term safety of calcium supplementation.
“Given calcium’s critical role in multiple physiological functions, including bone health, these results provide reassurance that long-term calcium supplementation did not increase dementia risk in older women,” she said.
Reference: “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” by Negar Ghasemifard, Joshua R. Lewis, Simone Radavelli-Bagatini, Simon M. Laws, Blossom C.M. Stephan, Jonathan M. Hodgson, Kun Zhu, Richard L. Prince and Marc Sim, 6 October 2025, The Lancet Regional Health – Western Pacific.
DOI: 10.1016/j.lanwpc.2025.101694
Funding: National Health and Medical Research Council of Australia.
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4 Comments
As a now eighty-one year old lay American male with a temporary history of inadvertently self-imposed serious calcium deficiency, in late 2010 with concurrent low bone density l learned the hard way of a few calcium factors not included in the article. First and foremost, the body will deny and/or rob the bones, nerves and/or teeth of calcium attempting to maintain the blood at an optimal pH (slightly alkaline, 7.35 to 7.45). Next, there are nearly subclinical non-IgE-mediated food allergy reactions (https://www.foodallergy.org/fare-blog/why-we-need-stop-referring-ige-mediated-allergies-true-food-allergies) which can be aggravated with officially (FDA in the US) approved food additives (e.g., MSG) to rapidly worsen, but still be very mild. Even partially avoiding dairy and meats long-term for allergy reasons, in conjunction with standard blood serum (as opposed to “ionic”) testing for calcium being unreliable (e.g., the pH factor), can result in a serious calcium deficiency, including short-term memory problems. Pregnancy can take a heavy toll on a woman’s calcium reserves. Estrogen is protective against uric acid and postmenopausal women are as at-risk of gout as younger men. Taking high doses of calcium carbonate (known to “bind” with phosphorus) long-term can cause a very serious phosphorus deficiency, including short-term memory problems. I wrote both JACI and The Lancet of my early findings in 2011, with both of them declining to publish what I wrote; outdated dogma prevails and the study is very seriously flawed.
Thanks for the information. I often feel pulled between traditional vs. functional medicine advice (body wise nerve pain went undiagnosed until imaging found cervical stenosis was irritating spinal sheath due to poor posture). I hope I am correct in saying too little calcium, as well as mega doses of calcium, if not needed, are dangerous. The mega dose calcium, with extra high blood level results has been shown to create issues either the heart (via solid, rigorous studies)
You’re welcome, Ann, for anything of value I’ve shared. Certainly, as mentioned above, mega doses of calcium carbonate, minimally, can be dangerous, albeit not necessarily as dementia in older women. I suspect calcium deficiency is much more pervasive than presently recognized.
I am 78 and have taken calcium supplements for 35 years; also a healthcare professional. This is the first time I ever heard calcium can cause dementia in older women. Not a commonly known datum.