Longitudinal study of calcium metabolism in male puberty. I. Bone mineral content, and serum levels of alkaline phosphatase, phosphate and calcium.

With the purpose of studying calcium metabolism at the growth spurt phase in puberty, bone mineral content (BMC) of the forearm, and serum concentrations of total alkaline phosphatase, phosphate, and calcium were determined in 36 boys every three months for about 2 years. BMC increased 35% throughout the study age period of 10.6 to 14.6 years, with a maximal rate between 12.8 and 13.8 years. In relation to growth velocity BMC rose steepest during the 12 months around peak height velocity (PHV) (p less than 0.001) and showed a progressive increase from 3 months before the first pubic hair stage (PH2) to PH4 (p less than 0.001). Serum alkaline phosphatase increased by a total of 55% throughout the age period with a diminished rate of increase from 13.5 to 14 years, around the PHV, and from PH3 to PH4.