Calcium absorption similar from supplements

provided by American College of Nutrition

new study on absorption of calcium from supplements finds that two different types of supplements were equally well absorbed and that the less expensive form of calcium carbonate was the more cost effective.

    In a study conducted at Creighton University in Omaha, Nebraska researchers gave 24 postmenopausal women 500 milligrams of calcium daily from plain calcium carbonate, pharmaceutically formulated calcium carbonate (Os-CalŪ) or pharmaceutically formulated calcium citrate. The last two products were over-the-counter supplements available in pharmacies. One time, the group was given an empty capsule as a control. All women also received sufficient vitamin D, which is important for optimum calcium absorption.

    Although a few studies gave the edge for absorption to calcium citrate, Robert P. Heaney, MD, senior investigator on this study and from the Osteoporosis Research Center at Creighton, said that “all three calcium sources were equally well absorbed and had equivalent bioavailability.”

    Several tests were conducted to assure that the calcium supplements proved equal. Calcium in the blood rose and parathyroid hormone was suppressed similarly following consumption of the three calcium sources. The use of vitamin D supplements assured that all test subjects had similar, adequate levels of that nutrient.

    Calcium is important in growth and maintenance of adequate bone mineral density. Thinning of the bones, or osteoporosis, afflicts millions of Americans, 80% of whom are postmenopausal women. Risk of hip and other fractures rises dramatically in people with osteoporosis. Estimates of current direct health care costs exceed $15 billion annually.

    Dr. Heaney stated that his cost-benefit analysis favors the less expensive calcium carbonate product. “Because calcium carbonate is less expensive than calcium citrate, treating all people 65 years or older with the carbonate form could save $478 million in health care costs annually.” The higher cost of calcium citrate would result in no net savings.

    The study appeared in the June, 2001 issue of the Journal of the American College of Nutrition. The research was funded both by Creighton University and Glaxo-SmithKline, makers of one of the tested calcium supplements.