Calcium supplementation trials and bone mass development in children, adolescents, and young adults.

The development of bone mass during childhood through young adulthood is an important determinant of bone health later in life, and calcium is the major building block. Most randomized, double-blind, placebo-controlled trials of calcium supplementation have been done in girls; however, calcium supplementation in boys has been investigated in recent studies. Positive short-term effects on bone measures during growth has been shown in boys and girls, particularly in weight-bearing appendicular bone, although the lifelong effect is not certain.