Table 1.
Baseline Characteristics by Race, Sex, and Locationa
| Variable | n | Overall Characteristics |
Differences,b P < .05 | ||||||
|---|---|---|---|---|---|---|---|---|---|
| Overall (n = 323) | White Males (n = 80) | Black Males (n = 82) | White Females (n = 78) | Black Females (n = 83) | Georgia (n = 160) | Indiana (n = 163) | |||
| Age, y | 323 | 11.3 (1.2) | 12.1 (1.0) | 11.8 (1.2) | 11.0 (1.0) | 10.5 (1.0) | 11.3 (1.2) | 11.4 (1.2) | B < W; F < M |
| Anthropometry | |||||||||
| Weight, kg | 323 | 47.4 (12.2) | 47.8 (13.8) | 49.4 (13.0) | 44.3 (9.3) | 47.8 (11.8) | 48.0 (11.8) | 46.7 (12.5) | |
| Height, cm | 323 | 151 (9.3) | 154 (9.7) | 152 (9.6) | 149 (8.8) | 148 (8.2) | 151 (8.9) | 151 (9.6) | F < M |
| BMI-for-age, % | 323 | 68.0 (29.2) | 56.6 (32.2) | 72.1 (26.1) | 66.2 (27.4) | 76.7 (27.3) | 70.3 (28.7) | 65.8 (29.6) | W < B; M < F |
| Body compositionc | |||||||||
| Fat mass, kg | 320 | 14.9 (7.4) | 13.6 (8.0) | 14.0 (7.5) | 14.4 (6.1) | 17.0 (7.6) | 14.2 (7.5) | 15.4 (7.3) | M < F |
| % body fat | 320 | 31.1 (9.4) | 28.2 (9.4) | 28.4 (9.5) | 32.6 (7.9) | 35.2 (8.7) | 29.7 (9.8) | 32.6 (8.7) | M < F |
| Lean mass, kg | 320 | 30.1 (6.9) | 32.2 (7.8) | 32.5 (7.6) | 28.2 (5.0) | 28.6 (5.4) | 31.6 (6.9) | 29.2 (6.6) | W < B; F < M |
| Biochemical | |||||||||
| 25(OH)D, nmol/L | 318 | 70.0 (18.6) | 80.6 (13.4) | 61.2 (14.6) | 79.6 (16.6) | 59.3 (18.0) | 72.0 (17.1) | 68.0 (19.8) | B < W; IN B < GA B |
| 1,25(OH)2D, pmol/L | 318 | 144 (42.8) | 130 (34.6) | 146 (46.4) | 147 (47.9) | 152 (38.6) | 146 (45.6) | 142 (39.9) | W < B; M < F |
| iPTH (pg/mL) | 318 | 27.4 (10.8) | 24.2 (9.0) | 28.4 (11.3) | 25.7 (9.2) | 31.1 (12.1) | 28.7 (11.4) | 26.1 (10.0) | W < B |
| Fractional Ca absorption | 311 | 0.44 (0.14) | 0.46 (0.14) | 0.39 (0.14) | 0.47 (0.13) | 0.45 (0.13) | 0.43 (0.14) | 0.45 (0.13) | B < W; M < F |
| Urine Ca (Ca/Cr) | 305 | 0.06 (0.08) | 0.07 (0.06) | 0.05 (0.05) | 0.08 (0.08) | 0.05 (0.12) | 0.06 (0.09) | 0.07 (0.07) | B < W |
| Serum Ca, mg/dL | 305 | 9.8 (0.3) | 9.7 (0.3) | 9.9 (0.3) | 9.9 (0.4) | 9.9 (0.3) | 9.8 (0.3) | 9.9 (0.4) | W < B; WM < WF; GA < IN |
| Dietary intake (per day) | |||||||||
| Energy, kcal | 307 | 2001 (556) | 2143 (541) | 2025 (602) | 1975 (543) | 1853 (505) | 1944 (528) | 2053 (577) | F < M |
| Vitamin D, IU | 307 | 169 (124) | 188 (163) | 168 (95) | 157 (121) | 162 (105) | 153 (101) | 184 (142) | GA < IN |
| Calcium (mg) | 307 | 901 (395) | 964 (417) | 849 (401) | 964 (419) | 825 (321) | 888 (373) | 912 (416) | B < W; GA M < IN M |
| Energy expenditure, METs/d | 304 | 62.2 (10.0) | 63.4 (9.0) | 61.3 (11.3) | 64.8 (10.2) | 59.3 (8.7) | 63.4 (10.5) | 61.1 (9.4) | B < W; IN B < GA B |
Abbreviations: B, black; F, female; GA, Georgia; IN, Indiana; M, male; W, white.
a
Values are presented as means (SD). Overall characteristics represent data collapsed across the 5 treatment groups.
b
Results of three-way ANOVA for race, gender, latitude, and all interactions investigated. Differences shown are significant at α = .05.
c
Body composition measures assessed using DXA.