Prevacid treats gastroesophageal reflux disease (GERD), ulcers and erosive esophagitis by reducing the amount of acid produced by the stomach. Also called lansoprazole, this drug can interfere with the absorption of calcium in the intestine. If you take calcium supplements and Prevacid, talk to your doctor about the best way to avoid decreased absorption of calcium.
The stomach produces hydrochloric acid to aid in the digestion of food. In some cases, the stomach produces too much acid, resulting in irritation of the stomach lining and the top portion of the small intestine. That irritation may result in gastrointestinal bleeding and ulcers. Prevacid reduces the amount of stomach acid produced by blocking an enzyme that aids in acid production. The reduced acid production gives existing ulcers time to heal, and prevents the formation of new ulcers. Reducing the amount of acid in the stomach also reduces the occurrence of heartburn and other symptoms of gastroesophageal reflux disease.
Calcium carbonate requires the presence of stomach acid to dissolve properly, according to the University of Arizona Cooperative Extension. When a person uses proton pump inhibitors like Prevacid, the amount of stomach acid decreases and the calcium does not dissolve properly. When the calcium does not dissolve properly, the intestines do not absorb as much as they should. For those who rely on calcium carbonate supplements to reduce the risk of osteoporosis, this means that less calcium enters the bloodstream to build strong bones. Because calcium also plays a role in muscle contraction, constriction and dilation of the blood vessels, and nerve impulse transmission, decreased absorption of calcium poses increased health risks for those who take Prevacid.
Dr. Douglas Corley, a gastroenterologist at San Francisco's Kaiser Permanente, conducted a study to determine the link between acid suppression therapy and an increased risk of bone fractures. During his study, Corley collected data for 33,752 people taking proton pump inhibitors and histamine-2 receptor antagonists. The study included data on 130,471 people who did not take these medications. Corley reports that the people with hip fractures were "30 percent more likely to be taking proton pump inhibitors" for more than two years. The increased risk jumped to 41 percent for those people taking more than one acid suppression pill each day. Dr. Corley presented the results of his study at Digestive Disease Week in 2009.
Because calcium citrate does not need stomach acid to dissolve properly, taking calcium citrate supplements instead of calcium carbonate supplements reduces the risk of poor calcium absorption. Take the supplements on an empty stomach for the best results.
Despite research that supports the claim that Prevacid and other proton pump inhibitors increase the risk for fractures, researchers must consider other medical factors when determining the effects of Prevacid on calcium absorption. In people with overactive parathyroid glands, excess parathyroid hormone causes blood calcium levels to increase. This leads to a loss of calcium in the bones, increasing the risk for fractures and osteoporosis. Studies to determine the impact of hyperparathyroidism on patients who take Prevacid could provide more information about the risks of this drug.