Table 1

 Characteristics of participants by categories of average cumulative total intake of calcium. Values are numbers (percentages) unless stated otherwise

CharacteristicsDaily total intake of calcium (mg/day)
<600600-9991000-1399≥1400
Participants2058 (3.3)38 388 (62.5)19 746 (32.1)1241 (2.0)
Mean (SD) age at entry (years)54.9 (10.3)53.9 (9.8)53.3 (9.5)53.6 (9.3)
Mean (SD) body mass index at entry (kg/m2)24.9 (4.3)24.7 (3.9)24.8 (3.9)24.3 (3.8)
Daily intake*:
 Total calcium (mean, mg)572 (150)933 (142)1243 (206)2137 (565)
 Total calcium (median, mg)54385910961514
 Calcium (mean, mg)533 (66)840 (99)1088 (105)1244 (271)
 Calcium (median, mg)†54285210741260
 Calcium supplementation†61 (16.7)4054 (17.6)5137 (35.4)803 (76.8)
 Calcium supplement use (500 mg calcium/tablet)†10 (2.7)394 (1.7)1472 (10.1)694 (66.4)
 Calcium containing multivitamin use (120 mg calcium per tablet)†54 (14.8)3785 (16.4)4290 (29.5)444 (42.5)
 Supplemental calcium (mean, mg)†107 (81)122 (90)241 (241)1063 (697)
 Vitamin D (mean, μg)4.1 (1.4)4.3 (1.2)4.7 (1.3)5.1 (1.6)
 Vitamin D supplementation†54 (14.8)3802 (16.5)4296 (29.6)448 (42.9)
 Supplemental vitamin D (mean, µg)†0.6 (1.6)0.7 (1.8)1.5 (2.6)2.9 (6.4)
 Retinol (mean, μg)930 (675)974 (601)1012 (559)1026 (541)
 Potassium (mean, mg)2695 (528)3018 (437)3253 (452)3421 (572)
 Alcohol (mean, g)2.7 (4.7)3.0 (4.0)2.8 (3.4)2.9 (3.6)
 Protein (mean, g)52.4 (22.9)62.6 (17.8)71.0 (18.8)77.4 (23.5)
 Total fat (mean, g)54.3 (10.5)56.2 (8.3)56.5 (8.6)55.5 (9.6)
 Energy (mean, kJ)6636 (2494)6778 (1891)6803 (1858)6945 (2117)
Leisure time physical activity level†‡:
 1 (lowest)100 (33.8)4202 (20.6)2425 (18.6)164 (17.7)
 252 (17.6)4883 (24.0)2975 (22.8)240 (25.8)
 381 (27.4)6678 (32.8)4552 (34.9)294 (31.7)
 431 (10.5)2362 (11.6)1587 (12.2)113 (12.2)
 5 (highest)32 (10.8)2232 (11.0)1488 (11.4)118 (12.7)
Smoking status:
 Current smoker†‡112 (32.2)5138 (22.8)3330 (23.4)251 (24.5)
 Non-smoker†‡66 (19.0)5066 (22.5)3325 (23.3)271 (26.5)
 Former smoker†‡170 (48.9)12 321 (54.7)7591 (53.3)502 (49.0)
Education:
 ≤9 years‡1710 (84.7)30 543 (81.0)15 175 (78.3)928 (76.1)
 10-12 years‡123 (6.1)2580 (6.8)1387 (7.2)85 (7.0)
 >12 years‡46 (2.3)1584 (4.2)1114 (5.8)78 (6.4)
 Vocational or other‡139 (6.9)3018 (8.0)1708 (8.8)128 (10.5)
Nulliparity280 (13.6)4083 (10.6)2021 (10.2)139 (11.2)
Living alone‡540 (26.4)8638 (22.7)4877 (25.0)377 (30.6)
Charlson comorbidity score:
 1285 (13.9)4166 (10.9)2121 (10.7)188 (15.2)
 ≥2182 (8.8)2978 (7.8)1541 (7.8)109 (8.8)
Fracture before baseline93 (4.5)1735 (4.5)951 (4.8)74 (6.0)
Hormone replacement therapy use†140 (38.4)10 070 (43.7)6801 (46.8)575 (55.0)
Cortisone tablet use†‡38 (15.0)1639 (10.4)1123 (11.0)150 (19.5)

*Energy adjusted cumulative average nutrient data was estimated with data from the 1987 and 1997 questionnaires.

†Information only available in 1997 questionnaire.

‡Incomplete data: at baseline (1987): educational level (n=60 346) and living alone (n=60 860); at second questionnaire (1997): leisure time physical activity level (n=34609), smoking status (n=38143), and cortisone use (n=27011).