Recently, a nice column outlined challenges related to prevention and treatment of bone loss due to osteoporosis, a serious public health problem. However, a critical contributor is often overlooked -- smoking.

We've known smoking was a risk factor for osteoporosis for more than 20 years, and recent studies show a direct relationship between tobacco use and decreased bone density and fractures.

The longer one smokes, the more cigarettes one consumes, the greater the risk of fracture in later years.

Smokers who do fracture can take longer to heal, with more complications, than nonsmokers.

Sixty-eight percent of those with osteoporosis are women. Women who smoke produce less estrogen and tend to experience menopause earlier than nonsmokers, leading to increased bone loss.

Even second-hand smoke exposure during youth has been implicated in developing low bone mass.

Quitting reduces the risk of bone thinning and fractures, but may take several years to lower a former smoker's risk.

We rightly advise people at risk for osteoporosis to exercise more and avoid sedentary living.

The risk produced by smoking is as high as that from a sedentary lifestyle, and we really shouldn't emphasize one while ignoring the other.

Jon Hauxwell