Calcium absorption efficiency and calcium requirements in children and adolescents.

Optimizing bone mass of young adults is important in the prevention of osteoporosis in later life. To achieve maximal peak bone mass, dietary calcium and its absorption need to be sufficient for skeletal growth and consolidation and for obligatory losses in urine, feces, and sweat. Direct measurements of skeletal accretion, obligatory losses, and of dietary calcium and absorption in children and adolescents have either not been done or are incomplete. From the measurements available and from extrapolated data in adults, it appears likely that many children and adolescents are not absorbing sufficient calcium in relation to their intake to achieve maximal bone mass.