Bone mass in the Norwegian population appears to be the lowest in Europe. Depending on which skeletal part is measured, from 14 to 36% of Norwegian women over the age of 50 suffer from osteoporosis according to the WHO definition. In a European multicentre study of the prevalence of vertebral deformities (the EVOS study), prevalence was the third highest among men and women from Oslo. Incidence rates of forearm and hip fractures are higher in Norway than in other countries. There are, however, differences in hip fracture incidence within Norway itself, with the highest rates occurring in urban areas. Body height is greater and body mass index lower than in other European countries. Vitamin D receptor allele polymorphism was found to have no influence on bone mass in two studies.