Abstract
Age related bone loss, osteoporosis and the subsequent development of fractures are important epidemiologic problems. The success of preventive treatment on bone loss will depend mainly on starting therapy and the correct time. The authors have measured Total Body Calcium (TBC) in 160 normal women aged between 20-80 years. No decrease in Total Body Calcium was found before age fifty years. Over the next thirty years TBC decreased from a mean of 1016 grams to 774 grams at an average annual rate of 1.3% per year. The authors were able to confirm that TBC did not change before the menopause by covariant analysis on this age group. Thus, in conclusion, the data support the concept that age related bone loss starts predominately at menopause and this would be the optimum time for starting preventive therapy.