Hi - This is a tough issue. Arimidex will almost definitely cause loss of bone density. You need to discuss this with your oncologist AND with a hone health specialist and possibly a nutritionist. You're in a tough situation: possible osteoporosis vs. a possible cancer recurrence.   The "trick" is to try to balance it all out so that NEITHER happens. You have to make sure you're getting sufficient calcium and D3, between your diet and supplements. You have to be doing weight-bearing exercise, which everyone can do, small-boned or not. And then you have to watch your bones carefully via regular DEXA-scans.   In my opinion, the most important thing you can do right now is get the correct medical team in place. don't let the oncologist dismiss your fears. Get your PCP or whoever is treating your osteopenia involved. Get all parties (including yourself) talking, and develop the plan that's right for YOU. Good luck - PJH