Osteoporosis in Children and Adolescents
During growth, the shape, architecture and strength of the bones are modulated by three major processes: growth, modelling and remodelling. Modelling is of particular interest as it appears that the bone is much more capable of responding to external loads during growth than at any other time. Remodelling also occurs during growth, but is limited, and does not participate in active growth, i.e. to accrue bone. Information on the pattern of bone mineral deposition is illustrated in Figs. 35.1 and 35.2, which show the plots and velocity curves of total body bone mineral content during growth. The authors of these longitudinal studies of boys and girls have also shown that, on average, 26% of adult total bone mineral was accrued during the 2 years around peak bone mineral content velocity, at average ages of 12.5 years for girls and 14.1 years for boys. Furthermore, it is of interest that true bone density does not increase with size or age, and reported increases in BMD with age are a reflection of growth and an increase in size rather than an increase in bone mineral per unit volume. The crucial importance of food in childhood to achieve optimal physical and cognitive development has long been acknowledged as has the recognition that the promotion of children’s health will help to reduce diet-related risks of many adult diseases, including degenerative and cardiovascular disorders, diabetes type 2, cancers, obesity and osteoporosis. Consequently, nutrition guidelines for children from 2 to 11 years have just been published: the Position of the American Dietetic Association.