Table 3.
Adjusted linear regression model for the association between immigration status and serum 25(OH)D (among children aged 1–6 years participating in TARGet Kids!, Toronto, Canada, December 2008 to July 2011)
| Child characteristic | Difference in serum 25(OH)D (nmol/l) | P value |
|---|---|---|
| Immigration (non-Western v. Western) | –0·04 | 0·99 |
| Age, months | −0·09 | 0·04* |
| Sex (male v. female) | –0·03 | 0·98 |
| Skin type (dark v. light) | −2·40 | 0·37 |
| BMI Z-score | –1·01 | 0·18 |
| Ethnicity | ||
| Mixed Western | Reference | 0·09† |
| East Asian & South-east Asian | –5·15 | |
| South-west Asian | −2·44 | |
| African & Caribbean | −14·54 | |
| Mixed Western/non-Western | –4·54 | |
| Season (winter v. summer) | −4.15 | 0.008* |
| Daily cow's milk intake, 250 ml (1 cup) | 5·00 | <0·0001* |
| Vitamin D supplementation (yes v. no) | 7·58 | <0·0001* |
| Outdoor play (1–4 v. 5–7 h/week) | 0·03 | 0·99 |
25(OH)D, 25-hydroxvitamin D.
*Indicates those variables that are independently associated with serum 25(OH)D (P < 0·05).
†The effect of ethnicity in the model was tested using mixed Western as the reference for the other four geographically based ethnic categories. The reported P value represents the statistical significance of a likelihood ratio test for all ethnicities tested in the model together relative to the reference.