Calcium Supplements and Dementia — Major Study Busts Long-Held Myth
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STORY AT-A-GLANCE
Calcium supplements were long feared to increase dementia risk, but new long-term research found no connection between calcium use and cognitive decline, even among women with heart disease or prior strokes
The 14.5-year study published in The Lancet Regional Health showed that calcium carbonate supplements did not raise dementia-related hospitalizations or deaths, dispelling decades of concern about vascular calcification or brain damage
Your brain and bones rely on nutrient synergy — calcium works best when paired with magnesium, vitamin D3, and vitamin K2, which ensure calcium strengthens bones instead of depositing in arteries or soft tissue
Keeping your calcium-to-phosphorus ratio near 1:1 is key for both skeletal and cognitive health, since excessive phosphorus from processed foods, soda and meat-heavy diets forces calcium out of bones and contributes to arterial calcification
The safest way to protect your brain and bones is through whole-food calcium sources such as raw grass fed cheese, yogurt, and eggshell powder, paired with balanced sun exposure and nutrient cofactors that keep calcium working where it should
For decades, older adults have been warned that taking calcium supplements could harm their brains. Those warnings stemmed from small observational studies suggesting calcium might increase dementia risk by promoting vascular calcification or white matter lesions in the brain. Dementia, meaning a progressive decline in memory, reasoning, and behavior that interferes with daily life, affects 57 million people worldwide, according to the World Health Organization.1
It’s a devastating condition that robs independence, identity, and connection — so it’s no surprise that any hint of increased risk sparks concern. Calcium, however, is not a nutrient you can simply eliminate. It’s the most abundant mineral in your body and foundational for bone density, heart rhythm, muscle contraction, and nerve signaling. You need enough of it every day, especially as you age.
Yet the debate over how to get it — through diet or supplements — has persisted for years. Some experts argued that supplementing calcium floods your bloodstream and triggers calcium deposits in blood vessels, leading to stroke or cognitive decline. Others maintained that the risk was overstated and lacked solid evidence.
That’s why researchers from the University of Western Australia and colleagues conducted one of the most comprehensive long-term studies to date to determine whether calcium carbonate supplements truly raised dementia risk.2 What they found directly challenges years of fear-driven headlines and changes how you might think about calcium and brain health.
Long-Term Calcium Supplement Use Found Safe for Brain Health
The post-hoc analysis published in The Lancet Regional Health investigated whether taking calcium carbonate supplements increased dementia risk in older women.3 Researchers followed 1,460 women aged 70 and older who were dementia-free at the start of the study.
Half took 1,200 milligrams (mg) of calcium carbonate daily for five years, while the other half received a placebo. After an additional 9.5 years of follow-up, the researchers found no difference in dementia-related hospitalizations or deaths between the two groups.
Older women were the focus because they face the highest risk of both osteoporosis and dementia — Calcium supplementation has long been prescribed to help offset accelerated bone loss in aging women.
<label class="hide-text" contenteditable="false">Text within this block will maintain its original spacing when published</label>However, past observational studies raised fears that supplements could promote calcium buildup in arteries and the brain. To address these concerns, researchers used hospital and death records to track dementia outcomes, providing a rigorous evaluation of calcium’s long-term neurological safety.
The results showed no increased risk of dementia, hospitalizations, or deaths — Over the study period, 18.4% of participants experienced dementia events — 16.6% were hospitalized for dementia, and 7.8% died from dementia-related causes.
<label class="hide-text" contenteditable="false">Text within this block will maintain its original spacing when published</label>However, the difference between calcium and placebo groups was statistically insignificant. Calcium users had slightly lower — but not significantly different — rates of dementia compared to the placebo group. This finding held true even after adjusting for genetic, cardiovascular, and lifestyle risk factors.
The researchers also found no effect from how well participants followed their supplement plan — Even among those who took 80% or more of their assigned tablets, known as the per-protocol group, calcium had no adverse effects on cognitive outcomes.
<label class="hide-text" contenteditable="false">Text within this block will maintain its original spacing when published</label>Compliance was similar between groups — about 57% overall — and those who adhered more closely to the treatment had a 27% lower relative risk of dementia, regardless of whether they were in the calcium or placebo group. This suggests healthier behavior patterns, not calcium intake itself, could explain differences in dementia outcomes.
Calcium’s Suspected Link to Dementia Was Largely Theoretical — and This Study Disproved It
Critics had speculated that calcium supplements could cause “intracellular calcium overload,” leading to cell death or calcified deposits in brain tissue. Others feared sudden spikes in blood calcium could damage blood vessel linings. However, no such effects were observed in this long-term controlled study. Researchers found no increase in carotid artery plaque or arterial wall thickening — two markers of vascular calcification — among supplement users.
The study also addressed previous contradictory research — Two earlier observational studies claimed calcium users had up to six times higher dementia risk, particularly among women with a history of stroke or brain lesions.4 5
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