TABLE 1.

Mean 25(OH)D concentrations and z scores at 5 time points during adolescence¹

Variable	Year 11: baseline (n = 99)2	Year 13 (n = 82)3	Year 15 (n = 76)4	Year 17 (n = 90)5	Year 20 (n = 76)6	P (ANOVA)
Age, y	11.6 ± 0.3	13.7 ± 0.2	15.6 ± 0.3	17.7 ± 0.2	20.8 ± 0.6
Height, cm	143 ± 7.3	155 ± 8.1	162 ± 8.7	165 ± 8.8	167 ± 7.9	<0.0001**
Height z score	−0.004 ± 0.10	−0.01 ± 0.10	−0.003 ± 0.10	0.001 ± 0.10	0.01 ± 0.10	1.00 (NS)
Weight, kg	37 ± 8.4	48 ± 11.2	57 ± 12.1	60 ± 12.2	64 ± 14.6	<0.0001**
Weight z score	−0.001 ± 0.10	−0.0004 ± 1.0	−0.003 ± 0.10	0.001 ± 0.10	0.003 ± 0.10	0.99 (NS)
BMI, kg/m2	18 ± 2.9	20 ± 3.6	22 ± 4.1	22 ± 4.1	23 ± 4.7	<0.0001**
BMI z score	−0.02 ± 1.0	−0.001 ± 1.0	−0.005 ± 1.0	−0.004 ± 1.0	−0.01 ± 1.0	0.99 (NS)
25(OH)D, nmol/L	58 ± 5.8*	58 ± 7.7*	55 ± 7.7	60 ± 7.7*	50 ± 7.2	<0.01**
25(OH)D z score	0.0001 ± 1.0*	0.05 ± 1.3*	−0.09 ± 1.3	0.19 ± 1.3*	−0.44 ± 1.2	<0.01**

¹All values are means ± SDs. *Significant difference between year 20 and other years [actual 25(OH)D values and 25(OH)D z scores] determined by a post hoc test. **Significant variations in mean height, weight, BMI, 25(OH)D, and 25(OH)D z scores by age determined by ANOVA. 25(OH)D, 25-hydroxyvitamin D.

²n = 90 black and 9 white.

³n = 76 black and 6 white.

⁴n = 69 black and 9 white.

⁵n = 81 black and 9 white.

⁶n = 70 black and 6 white.