Table 3.
Correlation coefficients between s-25(OH)D (nmol/l) and seasonal variable (n 158), physical variables (n 158) and intake variables (n 120); 7-year-old Icelandic girls and boys, Reykjavík, 2006
| Spearman's correlation (ρ) | P value (two-tailed)† | |
|---|---|---|
| Seasonal variable | ||
| Week of autumn (36–46) | ||
| Total | −0·50** | 0·41 |
| Girls | −0·57** | |
| Boys | −0·40** | |
| Physical variables | ||
| Height (cm) | ||
| Total | −0·06 | 0·25 |
| Girls | −0·12 | |
| Boys | −0·02 | |
| Weight (kg) | ||
| Total | −0·12 | 0·59 |
| Girls | −0·11 | |
| Boys | −0·18 | |
| BMI (kg/m2) | ||
| Total | −0·20* | 0·72 |
| Girls | −0·11 | |
| Boys | −0·27* | |
| CRF (W/kg per person) | ||
| Total | 0·34** | <0·001 |
| Girls | 0·36** | |
| Boys | 0·29** | |
| Serum PTH (nmol/l) | ||
| Total | −0·16* | <0·01 |
| Girls | −0·06 | |
| Boys | −0·25* | |
| Intake variables | ||
| Intake of fish-liver oil (ml/d) | ||
| Total | 0·28** | 0·03 |
| Girls | 0·32** | |
| Boys | 0·27* | |
| Intake of vitamin D (μg/d) | ||
| Total | 0·30** | <0·01 |
| Girls | 0·27* | |
| Boys | 0·32** |
s-25(OH)D, serum 25-hydroxyvitamin D; CRF, cardiorespiratory fitness; PTH, parathyroid hormone.
*Correlations are significant at the P = 0·05 level.
**Correlations are significant at the P = 0·01 level.
†P values are shown for gender differences. Gender differences were computed with the Mann–Whitney U test for week of autumn, BMI, vitamin D intake and fish-liver oil intake, and with the independent t test for height, weight and CRF.