Calcium Supplementation And Risk Of Dementia In Women With Cerebrovascular Disease, Neurology, August 2016

This was a group of 700 women, aged 70–92 years at the start of the study, dementia-free, in Sweden.

After 5 years:
Those who took calcium supplements had 2 to 4 times the risk of developing dementia than those who did not. But when they looked closer, the increased risk was mostly in women who had some blood flow disorder, such that…
Those who took calcium supplements – and who had some evidence of cerebrovascular disease – had 3 to 7 times the risk of developing dementia than those who did not.

Results: Women treated with calcium supplements (n = 98) were at a higher risk of developing dementia (odds ratio [OR] 2.10, 95% confidence interval [CI] 1.01–4.37, p = 0.046) and the subtype stroke-related dementia (vascular dementia and mixed dementia) (OR 4.40, 95% CI 1.54–12.61, p = 0.006) than women not given supplementation (n = 602). In stratified analyses, calcium supplementation was associated with the development of dementia in groups with a history of stroke (OR 6.77, 95% CI 1.36–33.75, p = 0.020) or presence of white matter lesions (OR 2.99, 95% CI 1.28–6.96, p = 0.011), but not in groups without these conditions.

Conclusions: Calcium supplementation may increase the risk of developing dementia in elderly women with cerebrovascular disease.

Why?

The mechanism of calcium supplements in the pathogenesis of dementia could be the steep increase in serum calcium levels caused by the supplements. Neurons located in areas of hypoperfusion might be especially vulnerable to the excitatory and excitotoxic effects of the calcium-level peaks caused by the supplementation.

It has been hypothesized that calcium supplements affect the vessels, and thus, may potentiate changes in the vessel walls in individuals with vascular disease, thereby leading to ischemia and hypoperfusion. Atherosclerosis is a long-term process with different stages, and calcium deposits become more common in the advanced stages. … The steep increase in serum calcium levels after calcium supplementation might lead to increased coagulability, lipohyalinosis, or altered vascular flow.

Another explanation may be that calcium supplementation stimulates vascular calcification by abnormal extraosseous deposition in atherosclerotic plaques.

Looks like … In a similar way that calcium supplements increase risk for heart attack, they increase risk for dementia.

Thank you, Melinda!