Osteoporosis, a condition in which the bones become porous and weak, is common in older people. As people age—and exacerbated, in women, by menopause—the cycle of bone restoration becomes disrupted. Ordinarily, the skeleton in a constant state of renovation and restoration, like a suspension bridge; some part is always adding new material and replacing worn-out material. However, for many people, the removal speeds up over time, or the replacement slows down, or both. This has no noticeable symptoms on its own, but it does contribute to the loss of height and posture seen as people age, as well as leaving the bones fragile and more prone to fracture.
This bone loss is more common in women than in men. In addition to osteoporosis related to menopause, that related to aging, which happens to people over 75, is twice as common in women than in men. Changes in the sex hormones that result from aging play a large role in the development of osteoporosis, and anything else that reduces the level of those hormones—breast cancer treatments that reduce estrogen levels, or prostate cancer treatments that have a similar effect on testosterone—can contribute to osteoporosis. Overactive thyroid, or thyroid medication to treat underactive thyroid, also increase the risk. People who take corticosteroid drugs for chronic inflammation often experience bone loss as well.
Preventing osteoporosis, for people at risk, means consulting a medical professional, particularly for people who take corticosteroids, have been treated for breast or prostate cancer, have experienced hormonal problems, or who have thyroid illness. There are some lifestyle changes that can also help ward off bone loss. A sedentary lifestyle is a risk factor for osteoporosis, and so getting exercise can help reduce the risk. Calcium and vitamin D, either in the diet or from supplements, can also prevent the condition from developing.
However, experts now say the foundation for osteoporosis in old age is laid in childhood, and so the foundation for bone health needs to be as well. While calcium and vitamin D later in life can help, they are particularly important in childhood. Many other risk factors, such as exercise and body weight, are likewise rooted in habits best developed while young.