Gastroesophageal reflux disease (GERD) or heartburn is a common malady.
The acid in the stomach irritates tissue where there isn’t the protective lining that the stomach has. If the acid gets outside the stomach, the patient feels pain or unease. Modern prescription drugs such as Nexium and Prevacid often work by interrupting the physiological mechanism of acid production and distribution, but the over-the-counter medicines for heartburn are antacids. The newer drugs are called proton-pump inhibitors or H2 inhibitors, but the old tried-and-true antacids still are widely used and work well for many people.
Antacids counteract acid by neutralizing it in a chemical sense. The pills are alkaline (aka bases) and the method of action is simple. Some antacids are prescription medications, but many are available over the counter and modern drug stores dedicate serious shelf space to these products. The antacids are almost always compounds of magnesium, calcium, or aluminum.
The obvious short-term side effects are in the digestive system, but in the long run with extended use they can have an effect on the skeletal system. Aluminum-containing compounds in particular have been known to result in detrimental changes to the bone as the aluminum displaces some of the body's calcium. Calcium-containing compounds, on the other hand, can have unintended good benefits as they essentially act as a dietary calcium supplement.
During the 1980s Tums, which consists of calcium compounds. aired television commercials touting this added benefit and reminding viewers that your body needs calcium anyway, so you might as well choose Tums.
Some of these drugs employ aluminum hydroxide or magnesium hydroxide as neutralization agents. These can bind with phosphate ions in the digestive system, essentially reducing the amount of phosphorus entering the body. In short term use this is not normally a problem, but chronic use may result in depletion of phosphorus in the body and softening of bones. Cases of osteopenia have been caused by excessive consumption of aluminum and magnesium compounds. http://www.ncbi.nlm.nih.gov/pubmed/9626411 Weak bones are typically caused by not enough calcium - calcium is the limiting nutrient and there is plenty of phosphorus. This is a situation where the bone softening was due to a lack of phosphorus.
There is some evidence of depletion of other trace minerals due to antacid use; these include zinc, copper, potassium, and iron. http://umm.edu/health/medical/altmed/depletion/antacids-aluminum-