Table 5.
Association between dietary calcium intake and risk of vertebral or forearm fracture in cohort studies
| Study | Fracture*/participants | Association | Groups | Risk or daily calcium intake† | Group 3 risk | Group 4 risk | Group 5 risk | Cut points between each group (mg/d)‡ or unit for pooled risk | |
|---|---|---|---|---|---|---|---|---|---|
| Group 1 | Group 2 | ||||||||
| Vertebral fracture | |||||||||
| van def Klift (M) 200444 | 44/1377 | Nil | 2 | 1162 (399) | 1148 (341) | — | — | — | No fracture; fracture |
| van def Klift (F) 200444 | 113/1624 | Nil | 2 | 1108 (333) | 1089 (305) | — | — | — | No fracture; fracture |
| Papaioannou 200546 | 34/5143 | Nil | 2 | 1133 (681) | 1274 (823) | — | — | — | No fracture; fracture |
| Nguyen 200752 | 76/924 | Nil | 2 | 583 (284) | 559 (292) | — | — | — | No fracture; fracture |
| Meier 200855 | 55/609 | Nil | — | 1.08 (0.77 to 1.51) | — | — | — | — | Per SD (322 mg/d) decrease |
| Cumming 199728 | 389/9704 | Nil | 4 | 1 | 1.2 (0.9 to 1.6) | 1.2 (0.8 to 1.8) | 1.5 (0.9 to 2.5) | — | 400; 800; 1200 |
| Nakamura (M) 200958 | NS/34 759 | Nil | 4 | 1.46 (0.82 to 2.61) | 1.20 (0.68 to 2.09) | 1.68 (1.02 to 2.74) | 1 | — | Q1; Q2; Q3; Q4 |
| Nakamura (F) 200958 | NS/41 120 | Inverse | 4 | 1.92 (1.28 to 2.88) | 1.30 (0.86 to 1.98) | 1.50 (0.99 to 2.26) | 1 | — | Q1; Q2; Q3; Q4 |
| Forearm fracture | |||||||||
| Nguyen (M) 200137 | 21/739 | Inverse | — | 1.98 (1.00 to 3.58) | — | — | — | — | Per 300 mg/d decrease |
| Nguyen (F) 200137 | 100/1105 | Nil | — | 1.01 (0.82 to 1.25) | — | — | — | — | Per 300 mg/d decrease |
| Diez-Perez 200748 | 104/5146 | Nil | 2 | 1.52 (0.74 to 3.12) | 1 | — | — | — | 250 |
| Cumming 199728 | 467/9704 | Nil | 4 | 1 | 1.0 (0.8 to 1.3) | 1.4 (1.0 to 2.0) | 0.9 (0.6 to 1.6) | — | 400; 800; 1200 |
| Owusu 199731 | 201/43 063 | Nil | 5 | 1 | 1.01 (0.66 to 1.55) | 0.75 (0.47 to 1.20) | 1.08 (0.70 to 1.68) | 1.11 (0.71-1.75) | 134; 248; 364; 591 |
| Honkanen 200034 | 368/11 798 | Inverse | 4 | 1 | 0.7 (0.53 to 0.92) | 0.61 (0.43 to 0.85) | 0.48 (0.25 to 0.92) | — | 500; 1000; 1500 |
| Kato 200036 | 193/6250 | Nil | 5 | 1 | 1.11 (0.7 to 1.7) | 0.93 (0.6 to 1.5) | 1.12 (0.7 to 1.7) | 0.78 (0.5-1.3) | 569; 689; 799; 949 |
Nil=no association between calcium intake and risk of fracture; inverse=higher calcium intake associated with decreased risk of fracture or lower calcium intake associated with higher risk of fracture; SD=standard deviation; M=male; F=female; Q=quartile (values not reported in paper); NS=not stated.
*Number of participants with vertebral fracture.
†Hazard ratio or relative risk (95% confidence interval) or mean (SD) mg/d.
‡For example, cut point of 250 indicates 2 groups of <250 and ≥250 mg/d; cut points of 400; 800; and 1200 indicate 4 groups <400; 400-799; 800-1199; ≥1200 mg/d.