The double blind, placebo-controlled study, lasting five years, looked at 1,460 women aged 70 or older who were supplemented with two 600 mg doses per day of calcium carbonate or placebo. During the study period, 16.1 percent of patients sustained one or more clinical osteoporotic fractures, with no reduction of fracture risk seen between the calcium and placebo groups. However, among the 830 patients who took 80 percent or more of their tablets, there was a significant reduction of fracture risk and improved bone structure and strength compared to placebo.

These results support the already strong body of evidence demonstrating calcium’s benefits in strengthening bones, preventing fractures and fighting osteoporosis. Most recently, the Women’s Health Initiative (WHI), a long-term government-sponsored study, reported results that on the surface appeared negative, but closer examination of the details revealed that these results, too, support the conventional wisdom that calcium helps strengthen bones—when the supplements are actually taken. In the WHI, only 59 percent of the participants were consistently taking their pills (either supplements or placebo). The results showed that the women who did take their pills regularly and had not been taking calcium before the study had a 29 percent lower risk of hip fracture.

“We are pleased to see that people are digging deeper into these studies and looking at compliance and other confounding factors,” said Andrew Shao, Ph.D., vice president, scientific and regulatory affairs for the Council for Responsible Nutrition (CRN). “The preponderance of scientific evidence reinforces the benefits of calcium supplementation.”

In addition to the AIM study, WHI, and a host of other data, an October 2004 Surgeon General’s report on bone health and osteoporosis noted that getting adequate levels of calcium, vitamin D and other nutrients like phosphate and magnesium, supports the body’s ability to build strong bones. The report also stated that 75 percent of Americans fall short of the recommended intake for calcium.

Says Dr. Shao, “Osteoporosis is a serious health risk, for both older men and women, and it’s encouraging to see more and more research supporting the valuable benefits of calcium supplementation. What we know is that calcium supplements are good for you—but you need to actually take them to reap the benefits.”