We've had a few threads on this topic...
I've known for 10 years I've had osteopenia; despite doing impact exercise for 15 years or so and weight lifting. I have never been a milk drinker, though and I have a huge family history of this. I couldn't take the Fosomax type drugs, which caused huge gastric problems. I was on Evista for 5 years on and off, which reversed it a bit, but I had all kinds of weird medical things that went away when i stopped taking it.
So, last year, it became full blown osteoporosis. In January I had a Reclast treatment, which is basically Fosomax, given IV, that stays in your body for a year, but by-passes your GI system. About half way through the 30 minute treatment, I felt dizzy and nauseous, so they stopped it. I had more than half the dose, though and my endo thinks it may have done at least some good. All my blood work came back fine, so I have none of the bad side effects that are possible.
I have a had a few minor crashes, the last being last summer, with no damage. I haven't been mountain biking fro a couple of years, but at this point, I feel like I want to go ahead and start again, since I'm not very aggressive at it, anyway.
I've been taking calcium and vitamin D supplements for 26 years, and nothing I did helped. I eat a very good diet, too. At this point, I feel like i can't let it rule my life.
Clock, I can't believe that there isn't more information about this in the UK.