CHICAGO - Judy Smith says she had five years without hot flashes while participating in a study of hormone supplements. But she quit taking them after results showed the pills could cause more harm than good. The symptoms returned for Smith and many other participants in a new survey, suggesting the pills might postpone but not prevent menopausal symptoms. “You can’t necessarily expect to just skip that stage” by taking hormones, said Dr. Judith Ockene of the University of Massachusetts Medical School, the survey’s lead author.