Information regarding bone mineral density (BMD) and related variations through prehistoric and historic time periods in Norway is scarce. We present results of BMD measurements of 222 individuals from four rural and urban burial sites representing the medieval and post-Reformation period using osteological analysis and dualenergy X-ray absorptiometry. Existing BMD data from 137 individuals dating to the Late Iron Age and medieval period were incorporated. Young medieval females have the highest mean BMD of all time periods, including the modern female population, and significant higher mean BMD than young females from the Late Iron Age (p = 0.02; q = 0.093). Mean BMD increased significantly from the Late Iron Age to the medieval period (p = 0.0002) followed by a significant decline from the medieval to the post-Reformation period (p = 0.014). The overall results reveal significant BMD variation through prehistoric and historic time periods in Norway. The patterns of age-related bone loss observed in the archaeological record are diverse with substantial temporal changes suggesting a transition towards a modern pattern. The bone loss often exceeds that observed in the population today. This study sheds light on long-term historical trends and patterns in Norway by examining BMD variation and age-related bone loss in adult life of males and females within three archaeological time periods and compared to present populations.