Osteoporosis is a rare but serious condition in children. One of the least well understood forms of childhood osteoporosis is idiopathic juvenile osteoporosis. Affected children suffer from pain, decreased activity tolerance, and increased fractures, including vertebral compression fractures. Even mild childhood osteoporosis may have long-term consequences since individuals who achieve a lower peak bone mass during the first 2-3 decades of life may be at increased risk for osteoporosis as adults.