Quintiles of energy adjusted maternal vitamin D intake | ptrend | |||||
Quintile | Q1 | Q2 | Q3 | Q4 | Q5 | |
Intake μg·day−1 | 0.74–2.32 | 2.32–2.90 | 2.90–3.51 | 3.51–4.68 | 4.69–35.0 | |
Postal questionnaire# | ||||||
Ever wheezed | 1 | 0.98 (0.60–1.61) | 0.74 (0.44–1.23) | 0.58 (0.34–0.99) | 0.51 (0.30–0.87) | 0.002 |
Wheeze in past year | 1 | 1.76 (0.94–3.30) | 1.12 (0.58–2.18) | 0.68 (0.33–1.41) | 0.59 (0.28–1.24) | 0.009 |
Wheezed in absence of a cold in past year | 1 | 1.27 (0.62–2.60) | 0.58 (0.25–1.33) | 0.60 (0.26–1.35) | 0.63 (0.28–1.41) | 0.056 |
Doctor confirmed asthma | 1 | 0.82 (0.46–1.46) | 0.59 (0.32–1.08) | 0.52 (0.28–0.98) | 0.60 (0.32–1.11) | 0.033 |
Asthma and wheeze in past year | 1 | 1.33 (0.65–2.71) | 0.74 (0.34–1.61) | 0.64 (0.28–1.44) | 0.63 (0.28–1.44) | 0.092 |
Medication to treat asthma in past year | 1 | 1.08 (0.57–2.04) | 0.76 (0.39–1.48) | 0.67 (0.34–1.34) | 0.74 (0.37–1.46) | 0.158 |
Augmented follow-up¶ | ||||||
Dispensed asthma medication in past year | 1 | 0.97 (0.58–1.64) | 0.83 (0.48–1.42) | 0.55 (0.30–1.00) | 0.76 (0.43–1.34) | 0.092 |
Longitudinal+ | ||||||
Wheeze in past year§ | 1 | 1.06 (0.77–1.47) | 0.95 (0.68–1.34) | 0.73 (0.52–1.03) | 0.66 (0.47–0.94) | 0.002 |
Doctor confirmed asthmaƒ | 1 | 0.87 (0.58–1.30) | 0.85 (0.56–1.28) | 0.63 (0.40–0.98) | 0.71 (0.45–1.11) | 0.046 |
Asthma and wheeze in past year§ | 1 | 1.15 (0.74–1.78) | 1.02 (0.64–1.62) | 0.62 (0.37–1.02) | 0.63 (0.38–1.07) | 0.007 |
Data are present as adjusted odds ratio (95 % CI), unless otherwise stated. Odds ratios were adjusted for maternal smoking during pregnancy, maternal atopy, birth order, child’s sex, maternal age at recruitment, Scottish Index of Multiple Deprivation, birth weight, birth crown-heel length, birth head circumference and maternal vitamin E intake. #: n=934; ¶: n=1748; +: 1, 2, 5 and 10 year data; §: generalised estimating equations; ƒ: discrete hazards modelling, hazard ratio.