Serious Eats - seriouseats.com

As RJGarcia mentioned there was a study conducted on consumption of cola and loss of bone density in women and men. The study showed a greater reduction in bone density in women who drank carbonated cola. However, when they published results the revealed that phosphoric acid may play a roll because it was present in the majority of sodas used in the test. So, there is an indication that carbonated cola ( cola was the main focus of the study, not merely carbonated soda) may effect bone density in women, but it is not conclusive since the presence of phosphoric acid was not taken into consideration.

Ultimately it's wise to drink more water than soda. Too much soda isn't good for many reasons. In order to get to the truth we would need a study done on women who drank carbonated soda, cola and beer, exclusively, for a prolong period. We shouldn't draw conclusions for beer based on a study done with carbonated cola, wherein they revealed that another factor may play a roll instead.

ktonltd mentioned adding sugar to a secondary fermentation. I'm a home brewer and I've never added sugar to a secondary. The bulk of the sugars effecting the final ABV of the beer should be added during the brewing process. Secondary fermentation is simply racking to a secondary vessel and letting the beer age for another week or so. Upon bottling a priming sugar is used (typically 3/4 cup for a 5 gallon batch) to revive the yeast and produced carbonation in the bottle.