Association among cardiorespiratory fitness, body fat, and bone marker measurements in healthy young females

Serum vitamin D (25-hydroxyvitamin D [25(OH)D]) is important for maintaining bone health, as well as for influencing a multitude of nonosseous effects. Associations between 25(OH)D and other bone marker measurements have not been well studied in relation to obesity and cardiorespiratory fitness in healthy young females. To determine if there is an association of cardiorespiratory fitness and body fat with bone marker measurements (ie, 25[OH]D and calcium) in healthy young females at peak bone mass. Females younger than 25 years were recruited as volunteer participants. From July 2007 to October 2007, participants were assessed for cardiorespiratory fitness by measuring maximal oxygen consumption (VO(2) max). In addition, their levels of serum 25(OH)D and serum total calcium were analyzed. Finally, percent body fat was measured using dual-energy x-ray absorptiometry of the whole body. Pearson correlation coefficients were used to evaluate the association of fitness and body fat with bone marker measurements. A total of 59 adolescent girls and young women-were recruited. A statistically significant, positive association was found between VO(2) max and serum 25(OH)D levels (Pearson r=0.36; P.05). Percent body fat was inversely associated with both VO(2) max (Pearson r= -0.70, P