Why does rapid bone loss occur after menopause?
Estrogen protects against bone loss. There is, in all of us, an age-related bone loss that starts probably in the 30s or 40s. With menopause, the drop in estrogen is associated with an accelerated bone loss that goes on at the rate of 1 percent to 2 percent per year for possibly 5 to 10 years. So it’s possible for a woman to lose 20 percent of her bone mass during that period. So if she goes into that period with a good bone mass that she acquired when she was young, that 20 percent bone loss will not cause problems. But if, as a young person, she didn’t get enough calcium or vitamin D or wasn’t physically active, or she had genetics that limited her peak bone mass, then even 10 percent bone loss could be a problem for her.
