Australian researchers report that a supplement containing 800 mg of calcium and 400 IU of vitamin D3 produced significant increases in the bone density and strength of peripubertal female identical twins, compared with placebo.
The study is published in the journal Osteoporosis International.
Osteoporosis is characterized by low bone mass, which leads to an increase risk of fractures, especially the hips, spine and wrists. An estimated 75 million people suffer from osteoporosis in Europe, the USA and Japan.
Women are four times more likely to develop osteoporosis than men.
Potential reduction of osteoporosis has traditionally been a two-pronged approach by either attempting to boost bone density in high-risk post-menopausal women by improved diet or supplements, or by maximising the build up of bone during the highly important pubescent years.
About 35 per cent of a mature adult's peak bone mass is built-up during puberty.
Researchers from the Australian Catholic University recruited 20 pairs of identical twins and randomly assigned one from each set of twins to receive the vitamin D, calcium combination, and the other to receive a placebo for six months.
The study, reportedly the first to use peripheral quantitative computed tomography (pQCT) to measure bone responses to the combined supplement in peripubertal children, found that the vitamin D and calcium combination was associated with increased bone density and bone strength in the shinbone (tibia) and in the arm (radius).
Indeed, shin and arm bone strength was improved by between 4 and 66 percent, depending on the specific site of the bone tested.
Strong supporting science
The study supports previous findings, including results from an 18-month randomised trial from scientists at the University of Sheffield in the UK (American Journal of Clinical Nutrition, February 2008, Vol 87, Pages 455-462).
In the Sheffield study, a daily 792 mg calcium supplement was associated with increases in bone mineral content and density. However, the effects were then reversed once supplementation was discontinued.
Commenting on the mechanism, the Sheffield scientists proposed that the mineral most likely worked by suppressing bone turnover.
Calcium is reported to be the biggest seller in the US supplements industry. Annual sales were about $993m (€836m) in 2004, according to the Nutrition Business Journal.
Source: Osteoporosis International
February 2011, Volume 22, Issue 2, Pages 489-98
“Calcium and vitamin-D supplementation on bone structural properties in peripubertal female identical twins: a randomised controlled trial”
Authors: D.A. Greene, G.A. Naughton