Quantitative measure of bone mineral content (BMC) loss is an important diagnostic indicator for determining the risk of fracture and in following the course of patients undergoing therapy for osteoporosis. Several techniques have been used to evaluate this parameter. Quantitative Computed Tomography (QCT) is the most precise and accurate method allowing selective measurement of trabecular compartment of the vertebrae. Age, sex, ethnic heritage and geographic factors influence BMC variability. The aim of this study is to describe the normal cross-section pattern of age-related spinal bone loss in a Southern Italy population (530 healthy subjects: 450 women, 80 men) and to provide a local data-base for better interpretation of the BMC values. The BMC of lumbar spine was measured by single energy QCT, using a reference phantom with five tubes containing known amounts of CaCO3, placed approximately at the vertebral bodies L2-L4. Results indicate an age-related bone loss with the lowest values at 55-70 years, particularly in women, while no major further decrease was observed in subjects over 65 years. Normal linear BMC decrease rate can be derived from this data.