(A) Boxplots of serum 25-hydroxyvitamin D and (B) parathyroid hormone levels in female Soldiers pre- and post-basic combat training by ethnicity. Serum 25-hydroxyvitamin D, 25(OH)D; parathyroid hormone, PTH; basic combat training, BCT. n = 74; non-Hispanic white, n = 39; non-Hispanic black, n = 24; Hispanic white, n = 11. Boxes represent the middle 50th percentile, and vertical lines extend to the 10th and 90th percentiles. Median values are marked by a line within each box. Values below the 10th percentile or above the 90th percentile are identified by solid circles (•). A two-factor repeated measures ANOVA with Bonferroni adjustments was utilized to determine the effects of time and ethnicity on 25(OH)D and PTH levels. Asterisks (*) indicate significant differences between mean values pre- and post-BCT within ethnicities (P < 0.05). adifferences between mean values of non-Hispanic whites and non-Hispanic blacks pre-BCT (P < 0.01); bdifferences between mean values of non-Hispanic blacks and Hispanic whites pre-BCT (P < 0.05); cdifferences between mean values of all ethnic groups post-BCT (P < 0.05).