TABLE 2.
Subject characteristics
| n* |
Vitamin D <50 nmol/l (n=29) |
Vitamin D ≥50 nmol/L (n=62) |
|||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|
| Lower quartile | Median | Upper quartile | Mean ± SD | n (%) | Lower quartile | Median | Upper quartile | Mean ± SD | n (%) | ||
| Age of child, months | 91 | 24.10 | 24.16 | 24.48 | 24.30±0.55 | 24.06 | 24.40 | 25.75 | 25.18±1.67 | ||
| Sex | 91 | ||||||||||
| Female | 14 (48) | 29 (47) | |||||||||
| Male | 15 (52) | 33 (53) | |||||||||
| Season of visit | 86 | ||||||||||
| Spring | 6 (22) | 24 (41) | |||||||||
| Winter | 21 (78) | 35 (59) | |||||||||
| Birth weight, kg | 90 | 3.18 | 3.36 | 3.60 | 3.31±0.42 | 3.04 | 3.23 | 3.47 | 3.32±0.42 | ||
| Maternal age, years | 91 | 33.0 | 37.0 | 38.0 | 35.1±4.6 | 32.0 | 35.0 | 38.0 | 34.3±4.4 | ||
| Maternal education | 91 | ||||||||||
| Public school | 0 (0) | 0 (0) | |||||||||
| High school | 4 (14) | 8 (13) | |||||||||
| University or college | 25 (86) | 54 (87) | |||||||||
| Daily cow’s milk intake (250 mL cups) | 79 | 0.98 | 1.50 | 2.00 | 1.40±0.67 | 1.25 | 1.75 | 2.06 | 1.73±0.64 | ||
| Daily juice intake (250 mL cups) | 72 | 0.25 | 0.75 | 1.00 | 0.70±0.45 | 0.31 | 0.50 | 0.75 | 0.65±0.54 | ||
| Bottle use | 85 | ||||||||||
| No | 22 (81) | 41 (71) | |||||||||
| Yes | 5 (19) | 17 (29) | |||||||||
| Daily snacking | 85 | ||||||||||
| No | 13 (48) | 28 (48) | |||||||||
| Yes | 14 (52) | 30 (52) | |||||||||
| Weight, kg | 85 | 11.8 | 13.0 | 13.6 | 12.6±1.2 | 11.5 | 12.1 | 1.3.4 | 12.5±1.4 | ||
| Body mass index, kg/m2 | 85 | 15.4 | 16.6 | 17.4 | 16.4±1.4 | 14.8 | 15.6 | 16.5 | 15.7±1.3 | ||
| Feeding at 9 months | 88 | ||||||||||
| Breast only | 7 (24) | 18 (31) | |||||||||
| Bottle only | 16 (55) | 29 (49) | |||||||||
| Breast and bottle | 6 (21) | 12 (20) | |||||||||
| Ever used vitamin D drops | 80 | ||||||||||
| No | 7 (28) | 14 (25) | |||||||||
| Yes | 18 (72) | 41 (75) | |||||||||
| Multivitamin use | 85 | ||||||||||
| No | 21 (78) | 37 (64) | |||||||||
| Yes | 6 (22) | 21 (36) | |||||||||
| Outdoor time, h/week | 85 | ||||||||||
| 0–4 | 16 (59) | 29 (50) | |||||||||
| >4 | 11 (41) | 29 (50) | |||||||||
| Always uses sunscreen | 85 | ||||||||||
| No | 10 (37) | 27 (47) | |||||||||
| Yes | 17 (63) | 31 (53) | |||||||||
| Skin pigmentation | 85 | ||||||||||
| 1–3 | 23 (85) | 48 (83) | |||||||||
| 4–6 | 4 (15) | 10 (17) | |||||||||
The lower quartile, median and upper quartile are for continuous variables.
*
Represents the number of nonmissing values