Table 3.
Serum 25(OH)D in relation to demographic or lifestyle-related parameters in the blood donors
| Serum 25(OH)D nmol/L mean ± SD |
Significance p value | |
|---|---|---|
| Women versus men | 65.6 ± 25.3 versus 61.0 ± 26.8 | 0.046 |
| Women versus men (when sunbed users were excluded) | 63.8 ± 22.9 versus 60.8 ± 27.0 | 0.20 |
| Age ≤ 29 versus ≥51 years (first quartile versus forth quartile) | 63.6 ± 30.2 versus 59.7 ± 21.8 | 0.213 |
| BMI ≤ 22.4 versus ≥26.8 kg/m2 (first quartile versus forth quartile) | 65.5 ± 26.3 versus 54.7 ± 22.2 | <0.001 |
| Smokers versus non-smokers | 51.4 ± 26.2 versus 63.4 ± 26.2 | 0.031 |
| Sunbed users versus non-users | 82.2 ± 35.6 versus 62.0 ± 25.5 | <0.001 |
| Subjects on a sunny holiday during the previous month, yes versus no | 86.9 ± 37.7 versus 61.1 ± 24.4 | <0.001 |
| Physically activea versus non-active | 64.5 ± 26.7 versus 58.4 ± 24.7 | 0.015 |
| Female study subjects using estrogensb versus non-users | 84.0 ± 38.3 versus 63.3 ± 22.2 | 0.016 |
| Vitamin D supplement users versus non-users (during the whole year) | 64.7 ± 19.5 versus 62.7 ± 26.9 | 0.49 |
| Vitamin D supplement users versus non-users (winter months only) | 59.0 ± 21.0 versus 49.2 ± 19.4 | 0.01 |
| Medication (other than vitamin D), users versus non-users | 70.3 ± 34.2 versus 61.9 ± 24.9 | 0.065 |
| Users of a vegetarian diet versus non-users | 59.7 ± 23.1 versus 63.0 ± 26.4 | 0.53 |
| Complementary and alternative medicine users versus non-users | 63.3 ± 21.8 versus 62.8 ± 27.0 | 0.87 |
25(OH)D 25-hydroxy vitamin D, BMI body mass index
aPhysically active defined as performing physical exercise regularly at least once a week
bestrogens were taken as contraceptives or hormone replacement therapy