Table 1.
Recent meta-analyses of randomized controlled trials on vitamin D supplementation and cancer mortality.
| First Author, Year, Reference | Databases Searched | Literature Searched Until | Number of Included Studies (References) | Included Participants | Cancer Deaths | Statistical Model for Pooling | RR (95% CI) |
|---|---|---|---|---|---|---|---|
| Keum 2019 [1] | PubMed, Embase | November 2018 | 5 [9,10,11,12,13] | 75,241 | 1107 | Random-effects | 0.87 (0.79–0.96) 1 |
| Haykal 2019 [14] | PubMed, Embase, CENTRAL | December 2018 | 5 [9,10,13,15,16] | 31,163 | 1533 | Random-effects | 0.87 (0.79–0.96) |
| Zhang X 2019 [17] | PubMed, Embase | August 2018 | 7 [9,10,11,12,13,18,19] | NR | 1763 | Random-effects | 0.87 (0.79–0.95) |
Abbreviations: RR, relative risk; CI, confidence interval; NR, not reported. 1 The meta-analysis includes a study that used an initial bolus and high monthly doses rather than daily supplementation. Pooling results without that study (Scragg et al. [12]) results in the same point estimate of cancer mortality reduction (0.87), however.