Table 1.
Baseline Characteristics of Daily D Health Study Participants (n = 604)
| 600 IU (n = 207) | 1000 IU (n = 190) | 2000 IU (n = 207) | |
|---|---|---|---|
| Age, y | 11.7 (1.4) | 11.7 (1.3) | 11.7 (1.5) |
| Female sex, no. (%) | 109 (52.7) | 89 (46.8) | 109 (52.7) |
| Race/ethnicity, no. (%) | |||
| White | 92 (44.4) | 81 (42.6) | 71 (34.3) |
| Black | 23 (11.1) | 28 (14.7) | 34 (16.4) |
| Hispanic or Latino | 42 (20.3) | 43 (22.6) | 50 (24.2) |
| Asian | 20 (9.7) | 17 (9.0) | 16 (7.7) |
| Multiracial or other | 30 (14.5) | 21 (11.1) | 36 (17.4) |
| Constitutive skin colora | 33.1 (25.1) | 30.9 (25.6) | 29.7 (25.8) |
| Facultative skin colora | 13.2 (23.8) | 11.2 (24.3) | 9.8 (24.6) |
| Height, cm | 149.5 (11.3) | 150.9 (11.2) | 151.1 (10.8) |
| Weight, kg | 48.7 (16.0) | 50.6 (15.9) | 50.0 (15.8) |
| Body mass index, kg/m2 | 21.3 (4.6) | 21.8 (5.0) | 21.6 (5.0) |
| Body mass index, z score | 0.78 (1.05) | 0.82 (1.14) | 0.79 (1.09) |
| Weight status, no. (%) | |||
| Normal | 107 (51.7) | 103 (54.2) | 114 (55.1) |
| Overweightb | 51 (24.6) | 33 (17.4) | 39 (18.8) |
| Obeseb | 49 (23.7) | 54 (28.4) | 54 (26.1) |
| Puberty, no. (%) | 67 (32.4) | 66 (34.7) | 78 (37.7) |
| Household income, no. (%) | |||
| <$30,000 | 92 (44.4) | 94 (49.5) | 103 (49.8) |
| ≥$30,000 | 102 (49.3) | 87 (45.8) | 88 (42.5) |
| Missing | 13 (6.3) | 9 (4.7) | 16 (7.7) |
| Free or reduced-price lunch eligible, no. (%) | 135 (65.2) | 131 (68.9) | 146 (70.5) |
| Dietary vitamin D, IU/d | 123.1 (80.9) | 141.0 (109.2) | 127.6 (87.1) |
| Vitamin D or multivitamin in past month, no. (%) | 17 (8.2) | 27 (14.2) | 27 (13.0) |
| Serum 25(OH)D status,c no. (%) | |||
| <12 ng/mL | 16 (7.7) | 7 (3.7) | 10 (4.8) |
| 12−19 ng/mL | 70 (33.8) | 65 (34.2) | 71 (34.3) |
| 20−29 ng/mL | 92 (44.4) | 104 (54.7) | 100 (48.3) |
| ≥30 ng/mL | 29 (14.0) | 14 (7.4) | 26 (12.6) |
Data are presented as mean (standard deviation) unless otherwise indicated.
a
Skin color was classified using individual typology angle: very light > 55 > light > 41 > intermediate > 28 > tanned > 10 > brown > −30 > dark (26).
b
Overweight was defined as 85th to 94th BMI percentile; obese was defined as ≥95th BMI percentile.
c
Serum 25(OH)D status was defined as follows: <12 ng/mL = severe deficiency; 12 to 19 ng/mL = deficiency; 20 to 29 ng/mL = insufficiency; ≥30 ng/mL = sufficiency.