Table 1.
Comparison of serum 25-hydroxyvitamin D (25(OH)D), lipid profile and duration of sun exposure between summer and winter in boys, girls and the total sample: 530 apparently healthy children aged 5–18 years from six Iranian provinces with a latitudinal gradient from 29°N to 37·5°N (summer, August–September; winter, February–March)
| Boys | Girls | Total sample | |||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Winter | Summer | Winter | Summer | Winter | Summer | ||||||||||
| Variable | Mean | sd | Mean | sd | P value | Mean | sd | Mean | sd | P value | Mean | sd | Mean | sd | P value |
| 25(OH)D (nmol/l) | 31·0 | 16·1 | 50·0 | 30·0 | <0·001 | 24·2 | 18·2 | 36·0 | 26·1 | <0·001 | 27·4 | 18·0 | 43·2 | 29·2 | <0·001 |
| TAG (mg/dl) | 87 | 49 | 86 | 44 | 0·77 | 80 | 36 | 83 | 31 | 0·08 | 83 | 43 | 85 | 38 | 0·22 |
| TC (mg/dl) | 140 | 28 | 140 | 31 | 0·71 | 141 | 25 | 143 | 29 | 0·11 | 140 | 27 | 141 | 30 | 0·37 |
| LDL-C (mg/dl) | 72 | 23 | 70 | 26 | 0·25 | 74 | 21 | 75 | 24 | 0·34 | 73 | 22 | 73 | 25 | 0·83 |
| HDL-C (mg/dl) | 51 | 12 | 53 | 12 | 0·03 | 51 | 10 | 53 | 11 | <0·001 | 51 | 11 | 53 | 11 | <0·001 |
| Sun exposure (%) | |||||||||||||||
| <1 h/d | 54·7 | 37·1 | <0·001 | 72·6 | 69·6 | 0·54 | 63·8 | 53·8 | 0·001 | ||||||
| >1 h/d | 45·3 | 62·8 | 27·4 | 30·4 | 36·2 | 46·2 | |||||||||
| Time of day of sun exposure (%) | |||||||||||||||
| 10.00–15.00 hours | 56·0 | 74·9 | <0·001 | 43·3 | 59·6 | <0·001 | 49·4 | 67·0 | <0·001 | ||||||
| Other | 44·0 | 25·1 | 56·7 | 40·4 | 50·6 | 33·0 | |||||||||
| Sunscreen use (%) | |||||||||||||||
| No | 98·1 | 97·7 | 1·00 | 91·5 | 90·7 | 0·5 | 94·7 | 94·1 | 0·25 | ||||||
| Yes | 1·9 | 2·3 | 8·5 | 9·3 | 5·3 | 5·9 | |||||||||
TC, total cholesterol; LDL-C, LDL cholesterol; HDL-C, HDL cholesterol.