Heaney R P
Department of Health Sciences, Creighton University, Omaha, NE 68178.
Calcif Tissue Int. 1991;49 Suppl:S42-5. doi: 10.1007/BF02555087.
Primary prevention of osteoporosis involves achieving the full genetic potential for bone mass. Secondary prevention is concerned with protecting what bone mass a woman may have at her current age. Calcium plays an important role in both. Calcium requirement varies with stage of growth, with physiological drains (e.g., pregnancy and lactation), and with factors that influence absorption and excretory loss (e.g., gonadal hormone status and sodium and protein intakes). The evidence is strong that prevailing calcium intakes contribute to the low bone mass component of osteoporotic fragility and that increases in intake would reduce the osteoporotic fracture burden. At the same time it needs to be emphasized that bone health is a multifactorial affair and that meeting calcium requirements alone will neither guarantee optimal bone growth nor protect against bone loss if other critical factors are missing. For example, calcium affords only minimal protection against either immobilization or estrogen withdrawal bone loss. Thus, while assuring an adequate calcium intake remains a sound strategy, it cannot be considered a total preventive for osteoporosis.
骨质疏松症的一级预防涉及实现骨量的全部遗传潜力。二级预防则关注保护女性在其当前年龄可能拥有的骨量。钙在这两方面都起着重要作用。钙的需求量会因生长阶段、生理消耗（如怀孕和哺乳）以及影响吸收和排泄损失的因素（如性腺激素状态、钠和蛋白质摄入量）而有所不同。有充分证据表明，目前的钙摄入量会导致骨质疏松性骨折易感性中骨量较低的部分，而增加钙摄入量会减轻骨质疏松性骨折的负担。同时需要强调的是，骨骼健康是一个多因素问题，如果缺少其他关键因素，仅满足钙的需求既不能保证最佳的骨骼生长，也不能预防骨质流失。例如，钙对因固定不动或雌激素缺乏导致的骨质流失仅提供极小的保护作用。因此，虽然确保充足的钙摄入量仍然是一个合理的策略，但它不能被视为预防骨质疏松症的万全之策。
