Heaney R P
Creighton University, Omaha, NE 68178-0650.
J Am Med Womens Assoc (1972). 1990 May-Jun;45(3):80-6.
Calcium requirement varies with stage of growth, with physiological drains (eg, pregnancy and lactation), and with factors that influence absorption and excretory loss (eg, gonadal hormone status and sodium and protein intakes). While for certain life-stages the cited requirement values are higher than currently recommended, they are below the intakes of both contemporary hunter-gatherers and our closest primate relatives, after adjusting for body size. Hence, they can be considered high only in comparison with current US practices. However, it also 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 panacea.
钙的需求量会因生长阶段、生理消耗（如怀孕和哺乳期）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。虽然对于某些生命阶段而言，所引用的需求值高于目前的推荐值，但在根据体型进行调整后，这些值低于当代狩猎采集者和我们最亲近的灵长类亲属的摄入量。因此，只有与美国目前的做法相比，它们才会被认为较高。然而，还需要强调的是，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，也无法预防骨质流失。例如，钙对因固定不动或雌激素缺乏引起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，但它不能被视为万灵药。
