Boy, we're really off-topic here. I think I might pull this whole section out and start a new thread in the waterbucket to clean up the original thread.
The issue with carbonated beverages is that most of them contain huge quantities of phosphates in the form of phosphoric acid. Calcium regulation in the body is closely tied to serum phosphate levels. When phosphate levels are high (such as in renal failure or excessive soda pop consumption), the body tries to get rid of calcium. Uptake of calcium from the intestine is also slowed down.
To see clinical long-term effects such as osteoporosis you'd need to drink colossal quantities of soda over a period of many years, but that certainly doesn't exclude many people here in the US.
With regards to bicarbonate, it's a pretty simple molecule and the body has many enzymatic mechanisms for producing it and breaking it down in various locations. It isn't transported across the lumen of the glomerulus or the lumen of the gut in its native form. The actual transport occurs as CO2. A little acid-base aqueous chemistry, mediated by enzymes, and presto......., for all intents and purposes, HCO3- is produced. The enzyme carbonic anhydrase (also present in plants, allowing them to extract carbon directly from carbonate) is involved in this process. | 
Hybrid Mode
