Acid Blockers Also Block Calcium

By Jeremy Appleton, ND, CNS

Healthnotes Newswire (March 9, 2006)—The ulcer drug omeprazole (Prilosec), which works by inhibiting the stomach’s production of hydrochloric acid, markedly decreases calcium absorption in older women, reports the American Journal of Medicine (2005;118:778–81).

In a randomized, double-blind trial, 18 elderly women took either 20 mg of omeprazole or placebo every day for a week and a daily multivitamin providing 400 IU of vitamin D, which is needed for calcium absorption. The women also took 500 mg per day of calcium in the form of calcium carbonate supplements that had been specially labeled to determine the exact amount of calcium absorption. Women in the omeprazole group had a 41% decrease in calcium absorption (61% if one outlying result was excluded) compared with those in the placebo group.

The absorption of calcium and several other nutrients is dependent on a sufficiently low pH (in other words, a more acidic environment) in the stomach. Excess stomach acid is no longer considered the cause of ulcers. Nevertheless, omeprazole (which belongs to a class of drugs called proton-pump inhibitors) is still popular because it can relieve ulcer symptoms; however, as the present study demonstrates, they may interfere with the absorption of calcium, a much-needed nutrient among senior women.

Most people think of stomach acid as being primarily used for the digestion of protein. But even when there is no food in the stomach, stomach acid is needed to maintain an acidic environment required for the absorption of nutrients, including calcium, iron, and vitamin B12. Inadequate stomach acid, therefore, can lead to nutrient deficiencies, which can contribute to anemia and other health problems. Stomach acid secretion also influences the pH of the small intestine and prevents the overgrowth of microorganisms from food. People with low stomach acid are more susceptible to bacterial or fungal overgrowth in their stomach or intestines.

The average American diet contains inadequate amounts of calcium, so most Americans, especially women, need calcium supplements. Low calcium intake increases the risk of bone loss and osteoporosis, and low calcium absorption has been associated with an increased risk of bone fractures. The addition of acid-blocking drugs could increase these risks for many older women

Jeremy Appleton, ND, CNS, is a licensed naturopathic physician, certified nutrition specialist, and published author. Dr. Appleton was the Nutrition Department Chair at the National College of Naturopathic Medicine, has served on the faculty at Bastyr University of Natural Health Sciences, and is a former Healthnotes Senior Science Editor and a founding contributor to Healthnotes Newswire. He has worked extensively in scientific and regulatory affairs in the supplement industry and is now a consultant through his company Praxis Natural Products Consulting and Wellness Services.

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