Table 3.
Incidence of Dementia During the 5-Year Supplementation Period According to Subgroup and Randomization Arm
| Endpoint | No. of Participants |
Placebo | 1 600 IU/d of Vitamin D3 | 3 200 IU/d of Vitamin D3 |
p Value for Trend |
p Value for Interaction | Combined Vitamin D Arms vs Placebo | p Value for Interaction |
|---|---|---|---|---|---|---|---|---|
| Men (events, n) | 1 424 | 7 | 7 | 5 | .614 | .347 | ||
| 1 | 0.83 (0.29–2.39) | 0.64 (0.20–2.02) | .486 | 0.74 (0.29–1.88) | ||||
| Women (events, n) | 1 068 | 11 | 7 | 8 | ||||
| 1 | 0.71 (0.28–1.84) | 0.79 (0.32–1.95) | .548 | 0.75 (0.34–1.63) | ||||
| Age < median 67.4 y (events, n) | 1 247 | 2 | 4 | 2 | .845 | .562 | ||
| 1 | 1.96 (0.36–10.7) | 1.02 (0.14–7.24) | .982 | 1.50 (0.30–7.43) | ||||
| Age ≥ median 67.4 y (events, n) | 1 245 | 16 | 10 | 11 | ||||
| 1 | 0.61 (0.28–1.36) | 0.66 (0.31–1.42) | .252 | 0.64 (0.33–1.22) | ||||
| BMI < median 26.4 kg/m2 (events, n) | 1 245 | 12 | 10 | 7 | .332 | .140 | ||
| 1 | 0.80 (0.34–1.85) | 0.53 (0.21–1.34) | .178 | 0.66 (0.31–1.38) | ||||
| BMI ≥ median 26.4 kg/m2 (events, n) | 1 243 | 6 | 4 | 6 | ||||
| 1 | 0.67 (0.19–2.38) | 1.10 (0.35–3.42) | .921 | 0.88 (0.32–2.42) | ||||
| BMI < 25 kg/m2 (events, n) | 849 | 7 | 8 | 7 | .206 | .075 | ||
| 1 | 1.00 (0.36–2.77) | 0.78 (0.27–2.23) | .692 | 0.88 (0.36–2.17) | ||||
| BMI = 25–30 kg/m2 (events, n) | 1 132 | 8 | 4 | 4 | ||||
| 1 | 0.50 (0.15–1.68) | 0.56 (0.17–1.88) | .264 | 0.53 (0.20–1.43) | ||||
| BMI ≥ 30 kg/m2 (events, n) | 507 | 3 | 2 | 2 | ||||
| 1 | 0.84 (0.14–5.08) | 0.75 (0.13–4.51) | .712 | 0.79 (0.18–3.56) |
Notes: Values are hazard ratios (95% confidence intervals) adjusted for age and sex in the Cox proportional hazards model. Four study participants did not report their weight and/or height and were excluded from the BMI subgroups. BMI = body mass index.