Menopause marks the end of fertile years for people with ovaries and usually occurs between ages 45 and 55 (the average age is 51 in the United States). During the menopausal transition, the ovaries' function starts to wind down, lowering estrogen and other hormone levels.

New and often unwelcome side effects can occur as hormone levels drop. Some of these effects are obvious—hot flashes and mood swings—but others are less apparent and happen more gradually with a lasting impact on your physical health.

Postmenopause is associated with an increased risk of osteoporosis. Of the estimated 10 million people in the United States with osteoporosis, 80 percent are women. Even more shocking: Roughly half of women older than age 50 break a bone because of osteoporosis.

Although one culprit is naturally smaller and thinner bones for women, a sharp drop in bone-protecting estrogen is