TABLE 1.
Baseline and trimester-specific characteristics of the sample1
| Characteristic | First trimester | Second trimester | Third trimester |
|---|---|---|---|
| Age, y | 32.1 ± 3.7 | ||
| Primiparous | 28 (35.4) | ||
| Prepregnancy BMI, kg/m2 | 25.7 ± 5.8 | ||
| Underweight | 2 (2.5) | ||
| Normal weight | 43 (54.4) | ||
| Overweight | 19 (24.1) | ||
| Obese | 15 (19.0) | ||
| Ethnicity—Caucasian2 | 77 (97.5) | ||
| Education | |||
| High school | 4 (5.0) | ||
| College | 13 (16.5) | ||
| University | 62 (78.5) | ||
| Household income, CAD | |||
| <60,000 | 15 (19.0) | ||
| 60,000–79,999 | 13 (16.5) | ||
| 80,000–99,999 | 17 (21.5) | ||
| ≥100,000 | 33 (41.8) | ||
| Income not disclosed | 1 (1.2) | ||
| Gestational age at sampling, weeks of gestation | 12.6 ± 0.8 | 22.5 ± 0.8 | 33.0 ± 0.6 |
| Season of sampling | |||
| Spring | 24 (30.4) | 12 (15.2) | 15 (19.0) |
| Summer | 26 (32.9) | 26 (32.9) | 15 (19.0) |
| Fall | 21 (26.6) | 25 (31.6) | 28 (35.4) |
| Winter | 8 (10.1) | 16 (20.3) | 21 (26.6) |
| Supplement use | |||
| Multivitamin | 61 (77.2) | 62 (78.4) | 61 (77.2) |
| Multivitamin only | 57 (72.2) | 58 (73.4) | 58 (73.4) |
| Multivitamin and vitamin D | 4 (5.1) | 4 (5.1) | 3 (3.8) |
| Vitamin D supplement only | 1 (1.2) | 0 | 0 |
| No supplement containing vitamin D | 17 (21.5) | 17 (21.5) | 18 (22.8) |
| Vitamin D intake, IU/d | |||
| Dietary | 235 ± 119 | 261 ± 135 | 272 ± 150 |
| Supplemental | 397 ± 531 | 428 ± 521 | 418 ± 517 |
| Total | 632 ± 556 | 690 ± 538 | 689 ± 545 |
| Servings of milk and alternatives,3 servings/d | 2.5 ± 1.1 | 2.7 ± 1.4 | 3.0 ± 1.4 |
| Physical activity level4 | |||
| Sedentary | 40 (50.6) | 52 (65.8) | 54 (68.4) |
| Low active | 14 (17.7) | 9 (11.4) | 11 (13.9) |
| Active and very active | 25 (31.6) | 18 (22.8) | 14 (17.7) |
Values are means ± SDs or n (%), n = 79. CAD, Canadian dollars; IU, international units.
Other ethnicities include Middle-Eastern (n = 1) and Venezuelan (n = 1).
According to the 2007 version of Canada's Food Guide (cheese, yogurt, cow milk, plant-based beverages fortified with vitamin D, etc.) (34).
Physical activity level was determined by categorizing participants according to the daily amount of time engaged in moderate- and high-intensity activities as follows: Sedentary, <30 min of moderate-intensity activity; Low active, 30–59 min of moderate-intensity activity; Active, 60–179 min of moderate- or 30–59 min of high-intensity activity; Very active, ≥180 min of moderate- or ≥60 min of moderate- plus ≥60 min of high-intensity activity. The Active and Very active categories were combined owing to their small sample sizes.