Maternal vitamin D dosage in multivitamins during pregnancy, period and duration of use and child's lung function at age 6–7 years
| Lung function at age 6–7 years | |||||
| No. of women | FEV1 z scores | FVC z scores | |||
| Crude B (95% CI) | Adj B* (95% CI) | Crude B (95% CI) | Adj B* (95% CI) | ||
| Vitamin D dosage/day during pregnancy | |||||
| 0 μg/day (reference) | 177 (40.6%) | 0.0 | 0.0 | 0.0 | 0.0 |
| <10 μg/day | 38 (8.7%) | −0.37 (−0.68 to −0.07) | −0.37 (−0.69 to −0.05) | −0.15 (−0.45 to 0.15) | −0.15 (−0.46 to 0.17) |
| ≥10 μg/day | 221 (50.7%) | −0.13 (−0.30 to 0.04) | −0.13 (−0.31 to 0.04) | −0.02 (−0.19 to 0.15) | −0.02 (−0.20 to 0.15) |
| p for trend | 0.16 | 0.16 | 0.83 | 0.83 | |
| Period of vitamin D containing multivitamin use during pregnancy | |||||
| No use at all (reference) | 177 (40.6%) | 0.0 | 0.0 | 0.0 | 0.0 |
| First trimester | 54 (12.4%) | −0.19 (−0.45 to 0.08) | −0.17 (−0.44 to 0.10) | −0.12 (−0.38 to 0.14) | −0.11 (−0.38 to 0.16) |
| Second and/or third trimester | 86 (19.7%) | −0.25 (−0.48 to −0.03) | −0.26 (−0.49 to −0.03) | −0.11 (−0.33 to 0.11) | −0.12 (−0.34 to 0.11) |
| All trimesters | 119 (27.3%) | −0.09 (−0.30 to 0.11) | −0.10 (−0.31 to 0.11) | 0.05 (−0.15 to 0.25) | 0.05 (−0.16 to 0.25) |
| Duration of vitamin D containing multivitamin use during pregnancy | |||||
| No use at all (reference) | 177 (40.6.%) | 0.0 | 0.0 | 0.0 | 0.0 |
| One trimester | 57 (13.1%) | −0.21 (−0.47 to 0.06) | −0.18 (−0.45 to 0.09) | −0.14 (−0.40 to 0.11) | −0.14 (−0.40 to 0.13) |
| Two trimesters | 83 (19.0%) | −0.24 (−0.47 to −0.02) | −0.25 (−0.49 to −0.02) | −0.10 (−0.32 to 0.13) | −0.10 (−0.33 to 0.13) |
| All trimesters | 119 (27.3%) | −0.09 (−0.30 to 0.11) | −0.10 (−0.31 to 0.11) | 0.05 (−0.15 to 0.25) | 0.05 (−0.16 to 0.25) |
| p for trend | 0.22 | 0.20 | 0.77 | 0.78 | |
Numbers in the table do not always add up to the total because of missing data.
↵* Adjusted for recruitment group, maternal age at delivery, maternal education level, maternal smoking during pregnancy, maternal alcohol consumption during pregnancy, birth weight, use of multivitamins at age 2 years, environmental tobacco smoke, physical activity at age 4–5 years and 6–7 years.
adjB, adjusted beta; FEV1, forced expiratory volume in 1 s; FVC, forced vital capacity.