TABLE 1.
Infant and mother baseline characteristics1
| Treatments |
||
| Variable | D2 | D3 |
| Mothers | ||
| Plasma 25(OH)D3,2 nmol/L | 68.3 ± 21.4 | 69.5 ± 21.7 |
| Age at delivery, y | 31.0 ± 4.5 | 32.6 ± 4.2 |
| Income ≥75,000 Canadian $, n (%) | 16 (61.5) | 13 (50.0) |
| Education, ≥university, n (%) | 20 (76.9) | 17 (65.4) |
| Infants | ||
| Male, n (%) | 12 (46.2) | 13 (50.0) |
| Born during vitamin D-synthesizing period (April 1–October 31), n (%) | 15 (57.7) | 15 (57.7) |
| Taking a vitamin D supplement at baseline, n (%) | 17 (65.4) | 21 (80.8) |
| Age started vitamin D supplement, d | 4 (3, 7) | 5 (3, 10) |
| White, self-identified,3 n (%) | 14 (58.3) | 21 (80.8) |
| Skin color (based on ITA°),4 n (%) | ||
| Very fair | 2 (7.7) | 3 (11.5) |
| Fair | 12 (46.2) | 12 (46.2) |
| Medium | 7 (26.9) | 11 (42.3) |
| Olive | 3 (11.5) | 0 (0.0) |
| Dark | 2 (7.7) | 0 (0.0) |
1
Values are frequency and percent or mean ± SD, n = 26. Non-normally distributed data presented as median (25th, 75th percentile). D2, ergocalciferol; D3, cholecalciferol; ITA, individual typological angle; LC-MS/MS, liquid chromatography tandem MS; 25(OH)D, 25-hydroxyvitamin D.
2
Results were tested by LC-MS/MS. The results were similar to LC-MS/MS when tested by immunoassay: D2: 74.0 ± 21.7 vs. D3: 79.6 ± 27.4; P = 0.42.
3
Based on mother’s and father’s race.
4
ITA° = {arc tangent [(L* − 50)/b*]} 180/3.14159, classified in 5 skin phototypes: dark (≤10°), olive (10–28°), medium (28–41°), fair (41–55°), and very fair (>55°). 1 g vitamin D = 40 ic.