秋月看这段，有助于我的Estrogen理论

Estrogen and Your Bones HRT and ERT are successful methods of combatting osteoporosis. As previously discussed, estrogen halts bone loss but cannot necessarily rebuild bone. Long-term estrogen use (10 or more years) may be required to prevent postmenopausal bone loss. Why estrogen helps protect the skeleton is still unclear. We do know that estrogen helps bones absorb the calcium they need to stay strong. It also helps conserve the calcium stored in the bones by encouraging other cells to use dietary calcium more efficiently. For instance, muscles require calcium to contract. If there is not enough calcium circulating in the blood for muscles to use, calcium is "borrowed" from the bone. Calcium is also needed for blood clotting, sending nerve impulses, and secreting various hormones. Prolonged borrowing from bone calcium for these processes speeds bone loss. That's why it's important to consume adequate amounts of calcium in your