TABLE 3.
Maternal and cord vitamin D metabolites and serum calcium and maternal iPTH throughout pregnancy, by treatment group1
| Treatment group2 | ||||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Baseline (14 wk mean gestational age) (n = 142) | Midpoint (24 wk mean gestational age) (n = 127) | Endpoint (36 wk mean gestational age) (n = 121) | Umbilical cord (n = 97) | |||||||||||||
| Placebo | 10 μg/d | 20 μg/d | P | Placebo | 10 μg/d | 20 μg/d | P | Placebo | 10 μg/d | 20 μg/d | P | Placebo | 10 μg/d | 20 μg/d | P | |
| Total 25(OH)D, nmol/L | 57.2 ± 24.5 | 49.6 ± 19.6 | 58.0 ± 22.9 | 0.13 | 63.6 ± 25.0a | 81.9 ± 27.8b | 92.8 ± 22.1b | <0.001 | 71.4 ± 24.3a | 96.0 ± 29.2b | 100.6 ± 23.3b | <0.001 | 39.2 ± 16.3a | 44.1 ± 14.6a,b | 50.5 ± 15.1b | 0.016 |
| 25(OH)D3, nmol/L | 54.8 ± 24.4 | 46.9 ± 19.7 | 54.9 ± 23.2 | 0.14 | 60.9 ± 25.1a | 79.1 ± 27.2b | 90.0 ± 21.9b | <0.001 | 68.4 ± 24.2a | 92.9 ± 28.9b | 97.6 ± 23.1b | <0.001 | 37.7 ± 16.2a | 42.4 ± 14.1a,b | 48.1 ± 14.1b | 0.023 |
| 3-Epi-25(OH)D3, nmol/L | 2.0 ± 1.2 | 1.6 ± 0.8 | 1.9 ± 1.3 | 0.30 | 2.6 ± 1.5a | 3.2 ± 1.6a | 4.1 ± 1.8b | <0.001 | 3.4 ± 1.5a | 4.5 ± 2.0b | 4.8 ± 1.7b | 0.001 | 3.8 ± 2.4 | 4.1 ± 1.8 | 4.6 ± 1.5 | 0.27 |
| 24,25(OH)2D3, nmol/L | 3.2 ± 2.0 | 2.7 ± 1.9 | 3.3 ± 2.1 | 0.35 | 3.9 ± 2.3a | 5.3 ± 2.6b | 6.2 ± 2.4b | <0.001 | 4.6 ± 2.5a | 7.3 ± 3.4b | 7.6 ± 2.5b | <0.001 | 2.9 ± 1.7a | 3.8 ± 2.1a,b | 4.0 ± 1.4b | 0.026 |
| Serum calcium,3 mmol/L | 2.21 ± 0.1 | 2.23 ± 0.1 | 2.24 ± 0.1 | 0.53 | 2.31 ± 0.1 | 2.31 ± 0.1 | 2.33 ± 0.1 | 0.609 | 2.31 ± 0.1a,b | 2.26 ± 0.2a | 2.36 ± 0.1b | 0.019 | 2.67 ± 0.2 | 2.61 ± 0.5 | 2.72 ± 0.2 | 0.40 |
| iPTH,4 pg/mL | 11.1 ± 10.7 | 11.2 ± 8.2 | 11.7 ± 8.8 | 0.95 | — | — | — | 13.6 ± 9.4 | 12.5 ± 11.8 | 11.9 ± 8.4 | 0.74 | — | — | — | ||
1Values are means ± SDs. P values are for differences between groups by ANOVA. Means in the same row without a common superscript letter differ, P < 0.05 (Tukey's test). P < 0.05 for change in 25(OH)D, 25(OH)D3, 3-epi-25(OH)D3, 24,25(OH)2D3, and serum calcium from baseline and P > 0.05 for iPTH. iPTH, intact parathyroid hormone; 3-epi-25(OH)D3, 3-epi-25-hydroxyvitamin D3; 24,25(OH)2D3, 24,25-dihydroxyvitamin D3; 25(OH)D, 25-hydroxyvitamin D; 25(OH)D3, 25-hydroxyvitamin D3.
2Represents total vitamin D intakes (including habitual diet plus supplemental vitamin D plus the treatment dose) of 12.1 ± 8.0, 21.9 ± 5.3, and 33.7 ± 5.1 µg/d in placebo and 10- and 20-µg groups, respectively.
3Serum albumin-corrected calcium values.
4Serum iPTH was not measured at midpoint.