Calcium and Vitamin D
Apr 27th 2005Wallabynerd alert
From a study in “Lancet”:
Prof Adrian Grant of the Health Services Research Unit at the University of Aberdeen and the study’s lead author, said: “We have found no evidence to suggest that calcium and vitamin supplements have a medical role to play as the only treatment in the prevention of secondary bone fractures.
Problem is, this isn’t quite the whole story.
This doesn’t mean that calcium and vitamin D aren’t good for bones — getting plenty of calcium helps by making sure that the body doesn’t start destroying bone to get enough, and it’s hard to go wrong with vitamin D. However, just consuming calcium and D won’t automatically keep bones healthy — mild exercise is probably at least as useful.
But then Prof. Grant goes on to say
“Instead, we need to consider other strategies for secondary fracture prevention, including pharmacological intervention with drugs such as bisphosphonates that help maintain bone density and reduce fractures.”
Only problem is that bisphosphonates don’t actually do the trick either, or at least not completely. They apparently work by suppressing the body’s natural cycle of bone rebuilding. (Normal, healthy bone is constantly being broken down, by cells called osteoclasts; the holes are then filled in with fresh material deposited by osteoblasts. This keeps the bone healthy and strong.)
With bisphosponate therapy, osteoclast activity is reduced. So, less bone is broken down — which sounds like a good thing. And yet, it turns out that as bone mineral gets older, the bone as a whole becomes more brittle. So, with bisphosphonate therapy one winds up with denser but more brittle bones.
Personally, I’ll stick to calcium and the gym.
