Plasma Concentrations of Vitamin D Metabolites in Puberty: Effect of Sexual Maturation and Implications for Growth*

Abstract

To relate the vitamin D metabolism in puberty to sex, sexual maturation, and, indirectly, to growth velocity and cessation of growth, the plasma level of 25-hydroxy vitamin D, 1,25-dihydroxyvitamin D [1,25-(OH)₂D], 24,25-dihydroxyvitamin D [24,25-(OH)₂D], and 25,26-(OH)₂D were measured in 191 adolescents representing all stages of puberty. In girls, 1,25- (OH)₂D₃ increased from age 11 yr to a peak at 12 yr of age (P2D concentrations were related to the stage of puberty, the girls showed a maximal increase between stages 1 and 2 (P<0.0005), with a peak at stage 3, whereas the boys had a significant increase from stage 2 to a peak at stage 3 (P<0.01). In both sexes, there were subsequent significantly decreasing values to stage 4 through stage 5. The ratio of 24,25- (0H)2D to 25-hydroxyvitamin D varied inversely with the 1,25- (0H)2D concentration, with the lowest value at age 12 yr in both sexes, followed by a gradual increase to a plateau at age 15 yr in girls and 17 yr in boys. It appears that the hormones of the vitamin D system add another dimension to the endocrinology of growth and puberty.