I had osteopenia in my 40's. Undiagnosed celiac disease most likely the cause. Also small build and low weight. Not a drinker. Over the years, the bone density chart continued its slow and two years ago precipitous decline. No amount of exercise, calcium or vit d was going to reverse the numbers. It was only when my endocrinologist said, "I'm getting very nervous about you" and did I tell you about the patient I have who refused meds, broke her hip, is still in a wheel chair two years later and may never get her independance back....The old scare tactic worked. I said okay Prolia me.

Good article, and especially the other one (from Readers Digest) that is linked to it.