Thursday, May 03, 2007

D problem with aging brains

Higher intakes of calcium and vitamin D have been promoted in recent years as a way to prevent bone loss with aging. We are concerned that some of this extra calcium may end up in the blood vessel walls rather than the bone.
--Dr. Martha Payne, Duke University

Dang, if it's not one thing, it's another. Just the other day, as I explained that calcifications seen on CT scans of coronary arteries were markers for significant coronary disease, a patient asked me if it was a problem then to take extra calcium. Oh no, I assured her, the calcifications were an injury response, not a result of dietary intake.

So now Dr. Payne and colleagues have studied the correlation between intake of calcium and vitamin D in a group of elderly subjects with the appearance of brain lesions on MRI scans. These lesions are believed to represent areas of atherosclerosis in small blood vessels causing an interruption of blood flow to the white matter in the brain.

Not only did they find a significant relationship between the intake of these two bone supportive nutrients, but the relationship remained when they statistically controlled for the effects of age, hypertension, diabetes, and heart disease. Further analysis suggested that the total volume of screwed-up brain areas was significantly associated only with D intake.

Too much of a good thing, perhaps.

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