Data Suggest Calcium Supplementation Is Not Linked to Dementia Risk in Older Women

Recent findings published in The Lancet Regional Health – Western Pacific provide compelling reassurance that calcium supplementation, commonly used for fracture prevention, does not increase the long-term risk of dementia in older women.¹

This analysis offers clarity to clinicians and pharmacists who have faced conflicting evidence from earlier observational studies. In previous reports, such as a Swedish cohort study, older women with cerebrovascular disease who took calcium supplements were found to have a 3% to 7% higher risk of dementia compared with those who did not take supplements.⁴ However, these findings were limited by confounding factors and lacked causal inference, underscoring the need for randomized trial data to clarify the association.

To address this question, the researchers of Edith Cowan University carried out a post hoc analysis of a randomized, double-blind, placebo-controlled trial for fracture prevention involving 1460 community-dwelling women aged 70 years and older.¹ The subjects were given either 1200 mg of elemental calcium daily in the form of calcium carbonate or a placebo for 5 years. After the supplementation phase, participants were followed by means of linked health records for a median of 14.5 years to capture hospitalizations and deaths related to dementia.¹

The investigators implemented the intention-to-treat and per-protocol analyses, lifestyle adjustment, dietary calcium intake, and genetic risk factors to reduce bias and determine whether calcium supplementation had any long-term effects on cognitive outcomes.¹

What Did They Find?

During the extended follow-up, 269 participants had dementia-related events, including 243 hospital admissions and 114 deaths attributed to dementia.¹ Comparing the calcium and placebo groups, no evidence of risk was found by the researchers in association with supplementation. The hazard ratio (HR) for all-cause dementia was 0.90, suggesting a slightly reduced risk for the calcium group, but not statistically significant.¹

In the case of dementia-related hospitalizations only, the HR was 0.89, and for dementia-related deaths, 0.78.¹ These similar results from various analyses provide strong support for no occurrence of an association with calcium supplementation that leads to an increased risk of dementia.

The research also involved confirmation of the participants' adherence, diet, and genetic predisposition, showing that even among those with strong compliance or higher baseline risk, a connection between calcium supplementation and incident dementia was not found.³

The researchers pointed out that they did not find a long-term risk of dementia following calcium supplement use for 5 years in elderly women, thus going against the previous warnings.³ They emphasized that the results give a signal only for older women and therefore cannot be extended to males, younger individuals, or different treatment combinations of calcium and vitamin D.³

What Does This Mean for Patients and Pharmacists?

Researchers suggest that these findings should reassure patients and health care professionals that calcium monotherapy appears cognitively safe in this population.^3,4 One of the primary points from the investigators is that this work is the most stringent study to date on the connection between calcium use and dementia, and it supports the idea that calcium supplementation should still be relied on for bone health.³

The findings also suggest that prior observational signals linking calcium to cognitive decline were likely spurious, confounded by factors such as preexisting cerebrovascular disease or health-seeking behavior differences among supplement users.⁴

This knowledge helps counter misinformation that might lead patients to avoid beneficial supplementation for bone health. Pharmacists should continue to emphasize adherence, monitor for potential adverse effects such as constipation or kidney stones, and assess for drug interactions, including with thiazide diuretics and certain antibiotics. While the study did not evaluate combined calcium–vitamin D therapy, such regimens remain widely used and generally safe when clinically indicated.

The study demonstrates that calcium supplementation for 5 years does not increase the long-term risk of dementia in older women over 14.5 years of follow-up.^1,3 These findings support continued use of calcium for fracture prevention without concern for adverse cognitive outcomes. Pharmacists play an essential role in counseling patients, dispelling misconceptions, and guiding evidence-based decisions on supplement use, ensuring that both bone and brain health are supported as patients age.

REFERENCES

1. Ghasemifard, Negar 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. Published October 6, 2025. Accessed October 8, 2025. https://www.thelancet.com/journals/lanwpc/article/PIIS2666-6065(25)00233-0/fulltext

2. Calcium supplementation linked to dementia risk in some women - Harvard Health. Harvard Health. Published October 17, 2016. https://www.health.harvard.edu/heart-health/calcium-supplementation-linked-to-dementia-risk-in-some-women

3. ECU research debunks link between calcium supplements and dementia. EurekAlert! Published October 7, 2025. Accessed October 8, 2025. https://www.eurekalert.org/news-releases/1100989

4. Calcium Supplements Do Not Raise Dementia Risk - Neuroscience News. Neuroscience News. Published October 7, 2025. Accessed October 8, 2025. https://neurosciencenews.com/calcium-supplements-dementia-29783