By Dr Thomas Levy
A bone density test, or bone densitometry, will reliably reflect the content of calcium in the bone being studied. When a younger person who has not been taking calcium supplements or ingesting large amounts of dietary calcium has a normal reading on such a scan, it can reasonably be assumed that there is no significant osteoporosis present, and it can also be assumed that the bone is of normal strength with a normal resistance to fracture. This is because the normal calcium content in the bone in a young healthy individual is also a reflection of normal amounts of related structural components in the bone as well.
However, when a higher score relative to a lower earlier score results following the extended administration of large amounts of calcium supplementation, it is only a reflection of increased calcium content in the bone, not of a normal structural matrix in the bone. Such bone only looks good, test-wise, but it has no greater resistance to fracture than of the earlier diseased bone before the new calcium deposition.
There is no question that baseline bone density tests are quite useful in the diagnosis of osteoporosis. Osteoporosis has lowered bony calcium content, and this decline in calcium content (along with the other components of the structural bony matrix) will always reflect a lowered bone density. However, when osteoporosis is being treated with increased calcium intake, the bone density can legitimately increase, but the quality of the bone does not improve unless other important factors are addressed.
With regard to the underlying osteoporosis, then, the increased bone density resulting from calcium supplementation is a cosmetic improvement only (just like a fresh coat of paint on a rotten fence). There continues to be no clear evidence that calcium supplements alone reduce fracture risk, regardless of what effect they might have on bone density.
Do you want to read more about deadly calcium myths? Read Death by Calcium.