It's not the asthma that causes this, but the medications that people with asthma use that can create this problem.
So your need for calcium increases...
See the following for more info. Hugs, Teri
http://www.osteo.org/newfile.asp?doc=r610i&doctitle=Asthma+and+Bone+Health&doctype=HTML+Fact+Sheet
Have you increased your calcium intake?
Please Check with Your Doctor about this before starting!!
Hugs, Teri