High Calcium, Vitamin D Intake May Harm Aging Brain

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In addition to ingesting it in supplement form, calcium can be found naturally in milk, cheese and broccoli, and is often added to fortify foods such as orange juice, cereals and breakfast bars.

Vitamin D, key to good calcium absorption, is produced by the skin following exposure to the sun, although production decreases with age. Vitamin D is also found in foods such as saltwater fish, liver and dairy products.

Payne's current work follows her earlier exploration into a similar association between large brain lesions and high intake of high-fat dairy products.

Having ruled out fat as the link between diet and lesions, Payne shifted her analysis towards calcium and vitamin D.

The researchers looked at MRI brain scans from 232 men and women, aged 60 to 86, all of whom showed brain lesions of varying sizes.

The scans were taken as part of a larger study on late-life depression. As a result, nearly half the participants were diagnosed with depression.

In addition to mental health status, vitamin D and calcium intake habits were noted along with age and blood pressure readings.

The researchers found that, even after accounting for all other mitigating factors, a "strong relationship" seemed to exist between total lesion volume and vitamin D and calcium consumption.

Payne and her associates believe the link may lie in an excess absorption of calcium by blood vessel walls. These could form bone-like deposits that narrow blood vessels and restrict elasticity. Excess vitamin D might exacerbate that process, they added.

In turn, blood vessel damage, if it were to occur in the brain, could lead to the development of brain lesions, they theorized.

Given that "higher intakes of calcium and vitamin D have been promoted in recent years as a way to prevent bone loss with aging", Payne said that more in-depth study is urgently needed to further test such possible explanations for the observed vitamin-lesion link.

But Harris said that no one should be unduly alarmed by the current findings, at least for the time being.

"You wouldn't want to change your intake of calcium and vitamin D based on this study," she advised. "It may generate some hypotheses that are worth testing, but at this point the research can't really speak to whether the brain lesions were related to the calcium, vitamin D, or some other factor that people with high intakes of calcium and vitamin D also have."

More information

For additional information on calcium and vitamin D, visit the National Osteoporosis Foundation.