Osteoporosis is a skeletal disorder characterized by a parallel loss of bone mineral and matrix which results in enhanced bone fragility and an increased risk of fractures. The associated fractures, and the morbidity and mortality that ensue, make osteoporosis a public health problem of enormous proportions. Clinical and research observations strongly suggest that most adult osteoporosis has its roots in childhood and have identified both genetic and environmental factors as central to the pathogenesis of this disorder.