This article about Diet Coke seems to suggest that there is a link between drinking cocoa cola (diet or not) and osteoporosis. Maybe it is no coincidence that my mother-in-law who has drunk regular coca cola every day most of her adult life has severe osteoporosis and is bent over these days. She used to stand 5 feet 8 inches, but has shrunk to closer to my height at 5 feet 3 inches (okay, I'm not measuring to see if I have shrunk. I don't want to know!)
Another vice of mine lately: I've been drinking diet coke too often and worrying about the aspartame at the same time. Let me tell you, it is very addictive, as anyone reading this probably already knows - more so than my drinking tea any day! That's it now! I'm reigning myself in before it is too late. Besides drinking sodas contributes to inflammation, Dr. Perricone says.
The experts are not sure exactly how colas affect calcium absorption and some speculate it may actually be the caffeine or the phosphoric acid, phosphorus or carbonation. I think it cannot be these last three if regular sodas don't do the same thing. What do you think? At any rate, if diet coke is your vice, take your calcium supplements or eat yogurt or whatever else you like containing calcium.