Researchers reporting in the British medical journal The Lancet, analyzed 44 studies on calcium supplementation or dietary calcium and bone fractures and concluded, “Dietary calcium intake is not associated with risk of fracture and there is no current evidence that increasing dietary calcium intake prevents fractures."
Qualifying studies included more than 44,000 people.
A different meta-study from New Zealand’s University of Auckland, also published in The Lancet, reviewed 59 clinical and observational studies of calcium and bone density. The meta-analysis compared the effect of calcium doses of 500, 800 and 1,000 milligrams per day and found that bone density improvements ranged between 0.6 and 1.8 percent throughout the body during the first year of supplementation, but did not increase over time.
They concluded that the improvements in bone mineral density from calcium supplements were small and that results mirrored the increases seen from dietary sources, suggesting that neither method significantly improves bone health.