Hey there good Gahalia,
Because I should be doing work right now, I decided to do a literature search on carbonated beverages causing osteoperosis. From what I can gather, you only have to worry about soda depleting your calcium if your bone actually comes in contact with the soda - generally considered unlikely.
Now I could be wrong, but I'd recommend soda hedonism (generic grape, not Coke or Dr. Pepper or root-beer or any of those) until someone lambasts my poor searching skills. If you're worried that I'm wrong, eat a healthy dose of tums after every soda - just not immediatly after.
Farewell,
Eug'if you know what I m'ene

P.S.
Whenever I think I'm overwhelmed in college, that's when I call on Jack Daniels to help me out. Sure, I remained overwhelmed, but it's a more light-hearted feeling of being overwhelmed.