IMO it can be a big mistake to just assume that hrt, diet and exercise is all you need to do to ward off osteopenia or osteoporosis. For a lot of women this will be true, but a lot of us will have a genetic predisposition to it, and it may not always be through a female link. Men are also prone to it, as my father was. He had no idea he had it until he suffered a broken hip, and from there it was a steady and painful decline until he died 3 years later. My GP told me that once an elderly person breaks a hip 3 years is about the limit.
When my bone density kept declining even though I was on hrt, exercising, taking calcium, vitamin d etc, I expressed my disappointment to my GP, and she said it was probably helping and things could have been worse without it, but it obviously wasn't enough.
So don't make assumptions ladies. Make sure you get yourself tested, because there are no symptoms - until you break something.
There is more to fear from osteoporosis than there is from a once a week fosamax tablet, because it is a medication that definitely works, and is best taken in the early osteopenia stage.