Table 2.
Distribution of participants by quartiles (Q) of vitamin D intake (FFQ) and serum 25-hydroxyvitamin D (25(OH)D) concentration among Portuguese adolescents aged 13 years (n 521), EPITeen (Epidemiological Health Investigation of Teenagers in Porto) cohort, 2003/2004 (weighted kappa=0·049)
| Serum 25(OH)D (ng/ml) | |||||||||
|---|---|---|---|---|---|---|---|---|---|
| Q1 (<14) | Q2 (14–16) | Q3 (17–20) | Q4 (>20) | ||||||
| Vitamin D intake (µg/d) | n | % | n | % | n | % | n | % | Total |
| Q1 (<2·78) | 55 | 10·6 | 25 | 4·8 | 32 | 6·1 | 19 | 3·6 | 131 |
| Q2 (2·78–4·02) | 42 | 8·0 | 21 | 4·0 | 29 | 5·6 | 38 | 7·2 | 130 |
| Q3 (4·03–5·40) | 47 | 9·0 | 27 | 5·1 | 30 | 5·8 | 26 | 5·0 | 130 |
| Q4 (>5·40) | 32 | 6·1 | 36 | 6·9 | 27 | 5·2 | 35 | 6·7 | 130 |
| Total | 176 | 109 | 118 | 118 | 521 | ||||