A Swedish study recently found that older women with a history of stroke or white matter lesions (WMLs) in the brain, who take calcium supplements, have an increased risk for dementia. We don't know whether the researchers factored in the amount of calcium in the diet of the study participants. (Sweden has the second highest milk consumption in the world.)
The researchers also found that calcium supplementation increased the risk of myocardial infarction and stroke. This finding confirms another dozen studies that found a higher incidence of heart disease in women who take calcium supplements.
Ironically, the women on calcium supplements had twice as many fractures, even though they were probably taking extra calcium to prevent broken bones.
Of course, these researchers are missing the magnesium connection. Calcium cannot build bones or prevent osteoporosis without adequate levels of magnesium. It’s as simple as that. When our bones are made entirely from calcium, they become brittle and can shatter, just like a stick of calcium carbonate chalk falling on the sidewalk. However, with the right percentage of magnesium, bone has the proper density and matrix that actually makes it flexible and more resistant to shattering. Many elderly people are suffering bone fractures because they have too much calcium and not enough magnesium. A 2014 meta-analysis concluded that low serum magnesium is a risk factor for osteoporosis among the postmenopausal group.
As for other conditions triggered or affected by calcium supplements – gall stones, heel spurs, and breast tissue calcification – remember that sufficient magnesium keeps calcium dissolved in the blood, and directs it properly to the bones so it will not precipitate in soft tissues of the body.