Table 1.
Characteristics of Participants, Overall and by Category of 25-hydroxyvitamin D Concentration. Data From 1591a Pregnant Women in Project Viva.
| Category of plasma25(OH)D (nmol/L) | ||||||
|---|---|---|---|---|---|---|
| Overall n=1591 |
< 25 n=81 |
25 -<50 n=472 |
50 -<75 n=743 |
≥75 n=295 |
||
| Mean (Standard Deviation) | P value | |||||
| Plasma 25(OH)D (nmol/L) | 58 (23) | 20 (18) | 39 (15) | 62 (11) | 90 (37) | <0.0001 |
| Maternal age at enrollment (years) | 32.1 (5.0) | 29.2 (6.7) | 31.5 (5.6) | 32.5 (4.6) | 32.9 (4.8) | <0.0001 |
| Prepregnancy body mass index (kg/m2) | 24.8 (5.4) | 28.8 (8.2) | 25.7 (6.4) | 24.1 (5.0) | 23.6 (4.7) | <0.0001 |
| Physical activity during pregnancy (hours/week) | 7.3 (8.2) | 9.6 (11.4) | 7.4 (8.4) | 7.0 (8.2) | 7.2 (7.2) | 0.11 |
| Gestational weight gain up to blood draw (kg) | 10.4 (4.3) | 8.6 (6.1) | 10.3 (4.9) | 10.7 (4.0) | 10.0 (4.4) | 0.13 |
| Second trimester calcium intake (mg/day) | 1427 (407) | 1250 (435) | 1328 (433) | 1480 (430) | 1499 (411) | <0.0001 |
| Second trimester fish intake (servings/week) | 1.6 (1.5) | 1.9 (2.2) | 1.6 (1.6) | 1.5 (1.5) | 1.6 (1.5) | 0.54 |
| n (%) | ||||||
| Race/ethnicity | <0.0001 | |||||
| Black | 225 (14.1) | 42 (51.4) | 93 (19.8) | 68 (9.2) | 22 (7.3) | |
| Hispanic | 96 (6.0) | 10 (12.5) | 37 (7.9) | 37 (5.0) | 11 (3.8) | |
| White | 1143 (71.8) | 21 (26.0) | 293 (62.0) | 579 (77.9) | 250 (84.9) | |
| Other | 127 (8.0) | 8 (10.1) | 49 (10.3) | 59 (7.9) | 12 (4.0) | |
| Smoking status | 0.01 | |||||
| Never | 1086 (68.2) | 60 (74.4) | 316 (67.0) | 508 (68.3) | 201 (68.5) | |
| Former | 317 (19.9) | 9 (10.7) | 88 (18.6) | 152 (20.4) | 69 (23.4) | |
| During pregnancy | 188 (11.8) | 12 (14.9) | 68 (14.4) | 84 (11.3) | 24 (8.1) | |
| Education | <0.0001 | |||||
| Less than college graduate | 517 (32.5) | 56 (68.8) | 190 (40.2) | 208 (28.0) | 64 (21.6) | |
| College graduate | 1074 (67.5) | 25 (31.2) | 282 (59.8) | 535 (72.0) | 231 (78.4) | |
| Marital status | <0.0001 | |||||
| Single | 109 (6.9) | 16 (19.2) | 45 (9.6) | 36 (4.8) | 12 (4.2) | |
| Married or cohabitating | 1482 (93.1) | 66 (80.8) | 427 (90.4) | 707 (95.2) | 282 (95.8) | 0.04 |
| Parity | ||||||
| 0 | 768 (48.3) | 28 (33.9) | 219 (46.4) | 376 (50.6) | 145 (49.3) | |
| > 0 | 823 (51.7) | 54 (66.1) | 253 (53.6) | 367 (49.4) | 149 (50.7) | |
| Season of last menstrual period | <0.0001 | |||||
| Winter | 315 (19.8) | 12 (14.4) | 69 (14.5) | 149 (20.1) | 85 (29.0) | |
| Spring | 388 (24.4) | 20 (24.1) | 121 (25.6) | 186 (25.1) | 61 (20.7) | |
| Summer | 434 (27.3) | 18 (22.4) | 130 (27.6) | 204 (27.4) | 82 (27.7) | |
| Fall | 454 (28.5) | 31 (39.1) | 152 (32.2) | 204 (27.4) | 67 (22.6) | |
Abbreviation: 25(OH)D, 25-hydroxyvitamin D