Table 4 Vitamin D related behaviors stratified by case and control groups
Variables | Cases (n = 130) | Controls (n = 195) | P-value* | ||
|---|---|---|---|---|---|
N | % | N | % | ||
Sun exposure and using of sun protection | |||||
 Do you work mainly: | |||||
  Indoor | 106 | 81.5 | 191 | 97.9 | .001 |
  Outdoor | 24 | 18.5 | 4 | 2.1 | |
 How much time do you often spend outdoors per day on weekdays? | |||||
  Not at all | 23 | 17.7 | 20 | 10.3 | .001 |
  ˂30 min | 58 | 44.6 | 126 | 64.6 | |
  30–60 min | 27 | 20.8 | 45 | 23.1 | |
   > 60 min | 22 | 16.9 | 4 | 2.1 | |
 How much time do you often spend outdoors per days on weekends? | |||||
  Not at all | 46 | 35.4 | 95 | 48.7 | .001 |
  ˂30 min | 48 | 36.9 | 46 | 23.6 | |
  30–60 min | 19 | 14.6 | 47 | 24.1 | |
   > 60 min | 17 | 13.1 | 7 | 3.6 | |
 Which parts of your body get exposed to the sun? | |||||
  Face | 0 | 0 | 0 | 0 | .001 |
  Hand | 12 | 9.2 | 29 | 14.9 | |
  Face & hand | 95 | 73.1 | 156 | 80 | |
  Both arms | 23 | 17.7 | 10 | 5.1 | |
  Both legs | 0 | 0 | 0 | 0 | |
  Completely covered | 0 | 0 | 0 | 0 |  |
 How often do you wear sunscreen while outdoors in the sun? | |||||
  Never | 129 | 99.2 | 156 | 80 | .001 |
  1–4 times/week | 0 | 0 | 23 | 11.8 | |
   > 5 times/week | 1 | 0.8 | 16 | 8.2 | |
The use of supplementation | |||||
 Do you take vitamin D supplements | |||||
  Yes | 18 | 13.8 | 21 | 10.8 | .403 |
  No | 122 | 86.2 | 174 | 89.2 | |
 Do you take calcium supplements? | |||||
  Yes | 4 | 3.1 | 9 | 4.6 | .488 |
  No | 126 | 96.9 | 186 | 95.4 | |
 Do you take multivitamin supplements? | |||||
  Yes | 1 | 0.8 | 13 | 6.7 | .010 |
  No | 129 | 99.2 | 182 | 93.3 | |
 Do you take calcium supplements with vitamin D? | |||||
  Yes | 1 | 0.8 | 5 | 2.6 | .239 |
  No | 129 | 99.2 | 190 | 97.4 | |
The intake of food rich in vitamin D | |||||
 How often do you drink milk? | |||||
  Never | 33 | 25.4 | 82 | 42.1 | .002 |
  1–2 times/week | 27 | 20.8 | 43 | 22.1 | |
  3–6 times/week | 27 | 20.8 | 37 | 19 | |
   ≥ once/day | 43 | 33.1 | 33 | 16.9 | |
 How often do you eat butter? | |||||
  Never | 113 | 86.9 | 132 | 67.7 | .001 |
  1–2 times/week | 12 | 9.2 | 40 | 20.5 | |
  3–6 times/week | 4 | 3.1 | 20 | 10.3 | |
   ≥ once/day | 1 | 0.8 | 3 | 1.5 | |
 How often do you eat eggs? | |||||
  Never | 21 | 16.2 | 32 | 16.4 | .998 |
  1–2 times/week | 95 | 73.1 | 142 | 72.8 | |
  3–6 times/week | 14 | 10.8 | 21 | 10.8 | |
   ≥ once/day | 0 | 0 | 0 | 0 | |
 How often do you eat oily fish (salmon, tuna, sardine)? | |||||
  Never | 66 | 50.8 | 72 | 36.9 | .034 |
  1–2 times/week | 44 | 33.8 | 73 | 37.4 | |
  3–6 times/week | 14 | 10.8 | 41 | 21 | |
   ≥ once/day | 6 | 4.6 | 9 | 4.6 | |
 How often do you eat liver? | |||||
  Never | 106 | 81.5 | 125 | 64.1 | .001 |
  1–2 times/week | 15 | 11.5 | 52 | 26.7 | |
  3–6 times/week | 7 | 5.4 | 18 | 9.2 | |
   ≥ once/day | 2 | 1.5 | 0 | 0 | |