Table 2. Subgroup analysis for dietary vitamin D intake and the risk of RCC.
| Sub-groups | Num. of sub-groups | RRs (95% CI) | I2 (%) | |
|---|---|---|---|---|
| Overall | 7 | 0.85 (0.75, 0.97) | 27.6 | |
| Study design | ||||
| Cohort study | 4 | 0.97 (0.77, 1.22) | 49.8 | |
| Case-control | 3 | 0.80 (0.67, 0.95) | 0 | |
| Locations | ||||
| United States | 3 | 0.81 (0.61, 1.06) | 0 | |
| Europe | 5 | 0.88 (0.75, 1.03) | 58.2 | |
| Gender | ||||
| Women | 4 | 0.70 (0.55, 0.88) | 0 | |
| Men | 4 | 1.02 (0.84, 1.25) | 41.1 | |
| Study quality | ||||
| High (NOS score 6) | 6 | 0.88 (0.74, 1.04) | 36.3 | |
| Low (NOS score ≤6) | 1 | 0.81 (0.63, 1.04) | – | |
| Adjustment | ||||
| Alcohol drinking | ||||
| Yes | 2 | 0.95 (0.75, 1.20) | 85.6 | |
| No | 6 | 0.81 (0.69, 0.97) | 0 | |
| Energy intake | ||||
| Yes | 6 | 0.97 (0.78, 1.22) | 47.6 | |
| No | 2 | 0.79 (0.66, 0.94) | 0 | |