Calcium Supplementation and Risk of Dementia in Women

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From: Neurology, October 2016

Quick Summary:

This study included 700 Swedish women aged 70-92 years old with a 5-year follow up to determine whether calcium supplementation is associated with the development of dementia. Dementia and osteoporosis are leading causes of disability in the elderly. Because calcium deficiency contributes to osteoporosis, daily dietary calcium intake of 1,000–1,200 mg is recommended. Such a large calcium intake through diet alone can be difficult; therefore, calcium supplements are widely used.  They found, “Women treated with calcium supplements had a higher risk of developing dementia (increased relative risk by 110%) and the subtype dementia with stroke (increased risk by 340%) than the women who did not take calcium supplementation.” It was also found that, “The frequency of fractures was 40.8% in the group that received calcium supplements and 20.8% in the group that did not.”

Abstract:

To determine whether calcium supplementation is associated with the development of dementia in women after a 5-year follow-up. This was a longitudinal population-based study. The sample was derived from the Prospective Population Study of Women and H70 Birth Cohort Study in Gothenburg, Sweden, and included 700 dementia-free women aged 70–92 years. At baseline in 2000–2001, and at follow-up in 2005–2006, the women underwent comprehensive neuropsychiatric and somatic examinations. A CT scan was performed in 447 participants at baseline. Information on the use and dosage of calcium supplements was collected. Dementia was diagnosed according to DSM-III-R criteria. 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. Calcium supplementation may increase the risk of developing dementia in elderly women with cerebrovascular disease. Because our sample was relatively small and the study was observational, these findings need to be confirmed.

These authors also note:

• Calcium supplementation may increase the risk of developing dementia in elderly women.
• “Calcium supplementation might have direct toxic effects on vulnerable neurons, because the increased calcium levels may amplify ischemic cell death and worsen the outcome after cerebrovascular events.”
• There is a steep increase in serum calcium levels caused by calcium supplements.
• Neurons are especially vulnerable to the excitatory and excitotoxic effects of the calcium-level peaks caused by the supplementation.
• “Calcium plays a central role in the mechanisms of cell death.”
• “Blocking calcium influx via NMDA receptors prevents both necrosis and apoptosis. This indicates the crucial role of calcium influx and intracellular calcium overload in the genesis of apoptosis and necrosis.”
• Calcium supplements may also potentiate changes in the vessel walls leading to atherosclerosis.
• “Calcium supplementation stimulates vascular calcification by abnormal extra-osseous deposition in atherosclerotic plaques.”