Table 1 Characteristics of the study population with serum 25(OH)D means in nmol/l and 95 % confidence intervalsa
Women (n = 3,635) | Men (n = 3,360) | |||||||
|---|---|---|---|---|---|---|---|---|
n | % | Mean (nmol/l) | 95 % CI | n | % | Mean (nmol/l) | 95 % CI | |
Age group (in years) | ||||||||
18-44 | 1277 | 35.1 | 49.6 | (46.6-52.7) | 1179 | 35.1 | 45.5 | (42.2-48.8) |
45-64 | 1452 | 39.9 | 44.1 | (42.2-46.0) | 1271 | 37.8 | 45.1 | (42.6-47.6) |
65-79 | 906 | 24.9 | 41.3 | (39.1-43.5) | 910 | 27.1 | 45.1 | (41.5-47.6) |
Season of examination | ||||||||
Spring (March-May) | 890 | 24.6 | 40.7 | (37.6-43.9) | 845 | 25.4 | 38.8 | (35.1-42.4) |
Summer (June-August) | 770 | 18.3 | 58.7 | (55.5-62.0) | 694 | 18.0 | 61.9 | (58.5-65.4) |
Autumn (Sept.-Nov.) | 1134 | 31.2 | 51.2 | (48.2-54.2) | 1073 | 32.4 | 51.5 | (47.5-55.4) |
Winter (Dec.-Feb.) | 841 | 25.9 | 35.4 | (33.2-37.5) | 748 | 24.2 | 31.3 | (29.1-33.5) |
Latitude | ||||||||
47°-49° | 1058 | 31.6 | 48.9 | (45.2-52.7) | 1000 | 31.2 | 49.3 | (44.8-53.8) |
50°-51° | 1658 | 44.5 | 44.1 | (41.4-46.7) | 1601 | 44.5 | 42.5 | (39.1-45.9) |
52°-54° | 919 | 23.8 | 45.3 | (40.5-50.1) | 759 | 24.3 | 45.1 | (39.7-50.5) |
Vitamin D intake index | ||||||||
Low intake | 1322 | 39.8 | 45.4 | (42.9-47.9) | 941 | 30.3 | 42.3 | (39.4-45.2) |
Intermediate intake | 1205 | 32.9 | 45.7 | (43.1-48.3) | 1067 | 31.3 | 46.5 | (43.4-49.6) |
Higher intake | 1019 | 27.3 | 46.4 | (43.8-49.0) | 1242 | 38.4 | 46.7 | (44.0-49.5) |
Use of vitamin D supplements | ||||||||
Yes | 221 | 5.9 | 55.9 | (51.7-60.2) | 45 | 1.0 | 60.3 | (52.5-68.1) |
No | 3414 | 94.1 | 45.3 | (43.2-47.4) | 3315 | 99.0 | 45.1 | (42.6-47.7) |
Oral contraceptive use | ||||||||
Yes | 480 | 15.3 | 54.5 | (49.9-59.1) | / | / | / | / |
No | 3155 | 84.7 | 44.3 | (42.4-46.3) | / | / | / | / |
Use of postmenopausal hormone therapy | ||||||||
Yes | 173 | 4.0 | 47.4 | (43.3-51.6) | / | / | / | / |
No | 3462 | 96.0 | 45.8 | (43.7-47.9) | / | / | / | / |
Body Mass Index (kg/m2) | ||||||||
<18.5 | 67 | 2.4 | 46.1 | (38.7-53.6) | 24 | 0.7 | 36.0 | (26.9-45.1) |
> = 18.5- < 25 | 1561 | 44.8 | 51.2 | (48.4-54.0) | 1011 | 32.1 | 47.5 | (44.5-50.6) |
> = 25- < 30 | 1111 | 29.2 | 44.1 | (41.8-46.3) | 1510 | 43.9 | 46.2 | (43.5-48.9) |
> = 30 | 867 | 23.6 | 37.6 | (35.6-39.6) | 796 | 23.3 | 40.2 | (37.3-43.1) |
Sport activity | ||||||||
No sport activity | 1119 | 33.3 | 41.4 | (38.8-44.0) | 1066 | 32.8 | 38.8 | (36.5-41.2) |
<2 h a week | 1645 | 44.8 | 47.0 | (44.7-49.2) | 1268 | 38.1 | 46.6 | (43.6-49.7) |
2- < 4 h a week | 545 | 14.9 | 52.3 | (49.1-55.4) | 518 | 15.6 | 51.1 | (47.5-54.7) |
> = 4 h a week | 240 | 7.1 | 52.8 | (47.5-58.1) | 405 | 13.4 | 53.1 | (49.6-56.7) |
Media consumption per day | ||||||||
TV, DVD, video | ||||||||
up to 1 h | 556 | 16.8 | 50.4 | (46.7-54.0) | 633 | 20.2 | 49.4 | (45.6-53.2) |
1- < 2 h | 1223 | 34.9 | 47.9 | (45.4-50.4) | 1145 | 36.0 | 47.4 | (44.4-50.4) |
2- < 3 h | 1224 | 33.5 | 44.7 | (42.0-47.3) | 1050 | 31.0 | 43.7 | (41.0-46.5) |
> = 3 h | 547 | 14.8 | 40.0 | (37.1-42.8) | 427 | 12.7 | 39.5 | (36.5-42.4) |
Computer, Internet, computer games, game consoles | ||||||||
up to 1 h | 2571 | 74.9 | 46.6 | (44.4-48.8) | 1995 | 60.6 | 47.8 | (45.2-50.4) |
1- < 2 h | 460 | 15.0 | 48.1 | (44.5-51.7) | 564 | 18.8 | 45.2 | (41.3-49.1) |
2- < 3 h | 136 | 4.6 | 47.5 | (40.9-54.1) | 274 | 10.1 | 43.9 | (39.8-48.0) |
> = 3 h | 159 | 5.5 | 44.2 | (40.2-48.1) | 265 | 10.5 | 40.3 | (35.7-44.9) |
Socio-economic status | ||||||||
Low | 587 | 20.0 | 39.5 | (36.6-42.4) | 516 | 19.0 | 40.7 | (37.3-44.0) |
Middle | 2261 | 62.1 | 46.9 | (44.5-49.2) | 1924 | 58.7 | 46.0 | (43.4-48.7) |
High | 765 | 17.9 | 50.3 | (47.3-53.4) | 897 | 22.3 | 47.7 | (44.5-50.9) |
Residential traffic | ||||||||
Living near a road with… | ||||||||
Very little traffic | 1414 | 39.9 | 47.1 | (44.6-49.5) | 1354 | 40.7 | 47.7 | (44.6-50.8) |
Fair amount of traffic | 988 | 27.1 | 46.9 | (44.2-49.6) | 935 | 28.8 | 45.3 | (42.5-48.0) |
Quite a lot of traffic | 357 | 10.1 | 46.2 | (42.4-50.1) | 308 | 10.1 | 44.4 | (40.0-48.7) |
Heavy traffic | 599 | 17.3 | 44.3 | (41.1-47.6) | 481 | 15.1 | 43.9 | (40.7-47.1) |
Extremely heavy traffic | 177 | 5.6 | 44.3 | (37.6-51.0) | 173 | 5.4 | 40.3 | (36.5-44.2) |