Table 2. Risk estimates on vitamin D status and non-Hodgkin lymphoma risk by different sources of exposure.
| Summary RR (95% CI) | Study no. | I2 | p-hetero | Begg's test | Egger's test | ||
|---|---|---|---|---|---|---|---|
| (a) Sunlight/UVR exposure | |||||||
| NHL | All | 0.80 (0.71–0.90) | 17 | 65.8% | 0.000. | 0.387 | 0.259 |
| Cohort study | 0.88 (0.72–1.06) | 6 | 76.6% | 0.001 | 0.707 | 0.793 | |
| Case-control study | 0.75 (0.68–0.82) | 11 | 38.9% | 0.090 | 1.000 | 0.835 | |
| NOS ≥7 | 0.80 (0.75–0.86) | 10 | 49.2% | 0.039 | 0.283 | 0.407 | |
| General population | 0.77 (0.72–0.82) | 14 | 42.1% | 0.048 | 1.000 | 0.450 | |
| DLBL | All | 0.72 (0.54–0.97) | 7 | 80.7% | 0.000. | 0.23 | 0.313 |
| Exc. Kleinstern [42] | 0.67 (0.53–0.84) | 6 | 58.4% | 0.035 | 0.06 | 0.031 | |
| FL | All | 0.81 (0.73–0.90) | 8 | 48.3% | 0.060 | 0.711 | 0.574 |
| Exc. Kleinstern [42] | 0.78 (0.70–0.88) | 7 | 26.7% | 0.225 | 1.000 | 0.982 | |
| CLL/SLL | All | 0.87 (0.68–1.11) | 6 | 54.6% | 0.051 | 0.707 | 0.796 |
| MZL | All | 0.70 (0.57–0.87) | 3 | 5.5% | 0.347 | n/a | n/a |
| B-cell | All | 0.84 (0.68–1.05) | 8 | 73.4% | 0.000. | 0.902 | 0.724 |
| Exc. Kleinstern [42] | 0.76 (0.68–0.85) | 7 | 43.5% | 0.101 | 1.000 | 0.661 | |
| T-cell | All | 0.70 (0.48–1.01) | 8 | 64.2% | 0.007 | 1.000 | 0.607 |
| (b) Dietary intake | |||||||
| NHL | All | 1.03 (0.90–1.19) | 9 | 56.9% | 0.018 | 0.466 | 0.084 |
| Cohort study | 1.03 (0.90–1.17) | 4 | 0.0% | 0.583 | n/a | n/a | |
| Case-control study | 0.995 (0.76–1.30) | 5 | 73.8% | 0.004 | n/a | n/a | |
| DLBL | Ref. by 200IU/d | 0.98 (0.81–1.20) | 7 | 0.0% | 0.550 | n/a | n/a |
| Ref. by max. intake | 0.98 (0.80–1.21) | 7 | 0.0% | 0.547 | n/a | n/a | |
| FL | Ref. by 200IU/d | 1.04 (0.81–1.33) | 7 | 45.9% | 0.085 | n/a | n/a |
| Ref. by max. intake | 0.96 (0.74–1.24) | 7 | 26.1% | 0.229 | n/a | n/a | |
| CLL/SLL | Ref. by 200IU/d | 0.95 (0.61–1.48) | 6 | 57.3% | 0.039 | n/a | n/a |
| Ref. by max. intake | 0.99 (0.73–1.33) | 6 | 41.4% | 0.130 | n/a | n/a | |
| MZL | Ref. by 200IU/d | 0.98 (0.54–1.77) | 2 | 0.0% | 0.612 | n/a | n/a |
| Ref. by max. intake | 0.91 (0.49–1.70) | 2 | 0.0% | 0.730 | n/a | n/a | |
| T-cell | Ref. by 200IU/d | 1.49 (0.84–2.66) | 3 | 0.0% | 0.642 | n/a | n/a |
| Ref. by max. intake | 1.55 (0.83–2.88) | 3 | 45.2% | 0.161 | n/a | n/a | |
| (c) Serum/plasma 25(OH)D | |||||||
| NHL | All | 0.97 (0.82–1.15) | 3 | 0.0% | 0.543 | n/a | n/a |
| Exc. Łuczyńska [17] | 1.01 (0.82–1.24) | 2 | 0.0% | 0.374 | n/a | n/a | |
| DLBL | All | 1.01 (0.74–1.37) | 2 | 0.0% | 0.437 | n/a | n/a |
| FL | All | 1.20 (0.83–1.72) | 2 | 0.0% | 0.453 | n/a | n/a |
| CLL/SLL | All | 0.82 (0.62–1.10) | 2 | 6.3% | 0.302 | n/a | n/a |
Meta-analyses results are presented in summary relative risks (RR) and their 95% confidence intervals (95% CI). Kleinstern et al. [42] is a study with influence on heterogeneity; Łuczyńska et al., [17] is a study with outcome in B-cell NHL (not NHL) but was included in line with a previous meta-analysis.