Effect of calcium on skeletal development, bone loss, and risk of fractures

In assessing the role of calcium, it must be stressed that calcium is not the cause of bone health but simply a necessary condition for it. It is mechanical usage that is of primary importance for bone. In just the same way iron is essential for hemoglobin synthesis and protein is essential for muscle mass, but neither is sufficient by itself. What, then, ought we to expect from a high calcium intake? Can we prevent estrogen-withdrawal bone loss? No. Calcium is not a substitute for estrogen, anymore than it is a substitute for exercise. Will calcium slow the remodeling loss that occurs with aging? Yes, to some extent; as calcium slows remodeling, it will inevitably slow remodeling-related loss. But most importantly, a high calcium intake will prevent calcium-deficiency bone loss. The only question, therefore, is the extent to which calcium deficiency loss may contribute significantly to bone fragility in various populations. The bone loss and fracture data reviewed briefly here indicate that an important portion of the osteoporotic fracture burden is calcium-related. What that portion is will be a function of the fraction of the population with inadequate intakes in any given country. Better than half of all adult American women have calcium intakes