Table 1.
The baseline characteristics of studies on vitamin D scrutinized in the research.
| First Author/Year | Cancer Type | Characteristics of the Primary Studies | Vit-D Exposure | Total Number of Studies (n) | Total Sample Size (n) | Outcome | NoP Studies Included for Incidence (n) | NoP Studies Included for Mortality (n) | Effect Size (ES) and Confidence Interval (CI) for Incidence | Effect Size (ES) and Confidence Interval (CI) for Mortality |
|---|---|---|---|---|---|---|---|---|---|---|
| Boughanem 2022 (a) x [21] | Colorectal cancer | Case-control, prospective cohort | Vit-D intake | 31 | 926,237 | Incidence | 12 | N/A | OR = 0.75 (0.67–0.85) | N/A |
| Boughanem 2022 (b) y [21] | Colorectal cancer | Case-control, prospective cohort | Vit-D intake | 31 | 926,237 | Incidence | 6 | N/A | HR = 0.94 (0.79–1.11) | N/A |
| Cheema 2022 [19] | Total cancer | RCTs | Vit-D intake | 13 | 109,543 | Incidence, mortality | 12 | 7 | RR = 0.99 (0.94–1.04) | RR = 0.93 (0.84–1.03) |
| Chen 2022 (a) [36] | Gastric cancer | Case-control, prospective cohort | Serum 25(OH)D | 11 | N/A | Incidence | 11 | N/A | OR = 0.93 (0.77–1.11) | N/A |
| Chen 2022 (b) [36] | Gastric cancer | Case-control, prospective cohort | Vit-D intake | 11 | N/A | Incidence | 4 | N/A | OR = 1.00 (0.86–1.16) | N/A |
| Ekmekcioglu 2017 [12] | Colorectal cancer | Case-control, prospective cohort | Serum 25(OH)D | 14 | 12,110 | Incidence | 14 | N/A | RR = 0.62 (0.56–0.70) | N/A |
| Gao 2018 [37] | Prostate cancer | Case-control, prospective cohort | Serum 25(OH)D | 19 | 48,369 | Incidence | 19 | N/A | RR = 1.15 (1.06–1.24) | N/A |
| Goulão 2018 [18] | Total cancer | RCTs | Vit-D intake | 30 | 18,808 | Incidence | 24 | 7 | RR = 1.03 (0.91–1.15) | RR = 0.88 (0.70–1.09) |
| Guo 2020 [13] | Liver cancer | Case-control, prospective cohort | Serum 25(OH)D | 6 | 60,811 | Incidence | 6 | N/A | RR = 0.78 (0.63–0.95) | N/A |
| Guo 2022 [20] | Total cancer | RCTs | Vit-D intake | 26 | 121,529 | Incidence, mortality | 19 | 11 | RR = 0.98 (0.94–1.02) | RR = 0.88 (0.80–0.96) |
| Han 2019 [38] | Total cancer | Prospective cohort | Serum 25(OH)D | 23 | 170,618 | Incidence, mortality | 8 | 16 | RR = 0.86 (0.73–1.02) | RR = 0.81 (0.71–0.93) |
| Haykal 2019 [39] | Total cancer | RCTs | Vit-D intake | 10 | 79,055 | Incidence, mortality | 9 | 5 | RR = 0.96 (0.86–1.07) | RR = 0.87 (0.79–0.96) |
| Hernandez-Alonso 2023 (a) [14] | Colorectal cancer | Case-control | Serum 25(OH)D | 28 | 140,112 | Incidence | 11 | N/A | OR = 0.61 (0.52–0.71) | N/A |
| Hernandez-Alonso 2023 (b) [14] | Colorectal cancer | Prospective cohort | Serum 25(OH)D | 28 | 140,112 | Incidence | 6 | N/A | HR = 0.80 (0.66–0.97) | N/A |
| Huncharek 2009 [40] | Colorectal cancer | Case-control, cohort | Vit-D intake | 60 | N/R | Incidence | 10 | N/A | RR = 0.94 (0.83–1.06) | N/A |
| Keum 2014 [41] | Total cancer | RCTs | Vit-D intake | 4 | 45,151 | Incidence, mortality | 4 | 3 | RR = 1.00 (0.94–1.06) | RR = 0.88 (0.78–0.98) |
| Khayatzadeh 2015 (a) [42] | Gastric cancer | Case-control, cohort | Vit-D intake | 7 | 59,626 | Incidence | 4 | N/A | OR = 1.09 (0.94–1.25) | N/A |
| Khayatzadeh 2015 (b) [42] | Gastric cancer | Case-control, cohort | Serum 25(OH)D | 7 | 59,626 | Incidence | 3 | N/A | OR = 0.92 (0.74–1.14) | N/A |
| Kim 2014 (a) [43] | Breast cancer | Case-control, cohort | Vit-D intake | 30 | 762,859 | Incidence | 12 | N/A | RR = 0.95 (0.88–1.01) | N/A |
| Kim 2014 (b) [43] | Breast cancer | Case-control, cohort | Serum 25(OH)D | 30 | 762,859 | Incidence, mortality | 14 | 4 | RR = 0.92 (0.83–1.02) | RR = 0.58 (0.40–0.85) |
| Lee 2011 [44] | Colorectal cancer | Case-control, cohort | Serum 25(OH)D | 8 | N/A | Incidence | 8 | N/A | OR = 0.66 (0.54–0.81) | N/A |
| Liao 2015 [45] | Bladder cancer | Case-control, cohort | Serum 25(OH)D | 5 | 89,610 | Incidence | 5 | N/A | RR = 0.75 (0.65–0.87) | N/A |
| Liao 2020 [22] | Ovarian cancer | Case-control, cohort | Vit-D intake | 29 | 963,604 | Incidence | 6 | N/A | RR = 0.80 (0.67–0.95) | N/A |
| Liu 2015 [46] | Colorectal cancer | Cohort | Vit-D intake | 47 | 870,330 | Incidence | 17 | N/A | RR = 0.87 (0.77–0.99) | N/A |
| Liu 2017 (a) [23] | Lung cancer | Case-control, cohort | Vit-D intake | 22 | 813,801 | Incidence | 6 | N/A | OR = 0.89 (0.83–0.97) | N/A |
| Liu 2017 (b) [23] | Lung cancer | Case-control, cohort | Serum 25(OH)D | 22 | 813,801 | Incidence, mortality | 8 | 3 | OR = 0.72 (0.61–0.85) | OR = 0.39 (0.28–0.54) |
| Liu 2018 (a) * [47] | Pancreatic cancer | Case-control, cohort, RCTs |
Vit-D intake | 25 | 1,213,821 | Incidence | 11 | N/A | RR = 0.90 (0.83–0.98) | N/A |
| Liu 2018 (b) ** [47] | Pancreatic cancer | Case-control, cohort, RCTs |
Vit-D intake | 25 | 1,213,821 | Incidence | 14 | N/A | RR = 0.79 (0.73–0.85) | N/A |
| Lopez-Caleya 2022 [48] | Colorectal cancer | Case-control | Vit-D intake | 55 | 55,522 | Incidence | 23 | N/A | OR = 0.96 (0.93–0.98) | N/A |
| Maalmi 2014 *** [49] | Breast cancer | Cohort | Serum 25(OH)D | 5 | 4413 | Mortality | N/A | 3 | N/A | HR = 0.57 (0.38–0.84) |
| Maalmi 2018 *** [50] | Colorectal cancer | Cohort | Serum 25(OH)D | 11 | 7718 | Mortality | N/A | 6 | N/A | HR = 0.67 (0.57–0.78) |
| Pu 2021 (a) [51] | Head and neck cancer | Case-control, cohort | Vit-D intake | 16 | 81,908 | Incidence | 3 | N/A | OR = 0.77 (0.65–0.92) | N/A |
| Pu 2021 (b) [51] | Head and neck cancer | Case-control, cohort | Serum 25(OH)D | 16 | 81,908 | Incidence, mortality | 5 | 3 | OR = 0.68 (0.59–0.78) | OR = 0.75 (0.60–0.94) |
| Shahvazi 2019 [52] | Prostate cancer | Clinical trials | Vit-D intake | 22 | 1902 | Mortality | N/A | 3 | N/A | RR = 1.05 (0.81–1.36) |
| Sun 2021 (a) [24] | Lung cancer | Case-control, cohort, RCTs | Serum 25(OH)D | 40 | 1,566,662 | Incidence, mortality | 16 | 9 | RR = 0.91 (0.84–0.98) | RR = 0.71 (0.53–0.97) |
| Sun 2021 (b) [24] | Lung cancer | Case-control, cohort, RCTs | Vit-D intake | 40 | 1,566,662 | Incidence | 4 | N/A | RR = 0.90 (0.80–1.03) | N/A |
| Wei 2018 (a) [53] | Lung cancer | Case-control, cohort | Serum 25(OH)D | 16 | 280,127 | Incidence | 12 | N/A | RR = 1.04 (0.94–1.15) | N/A |
| Wei 2018 (b) [53] | Lung cancer | Case-control, cohort | Vit-D intake | 16 | 280,127 | Incidence | 5 | N/A | RR = 0.85 (0.74–0.98) | N/A |
| Xu 2021 [54] | Colorectal cancer | Case-control, cohort | Vit-D intake | 25 | 911,638 | Incidence | 21 | N/A | OR = 0.87 (0.82–0.92) | N/A |
| Zhang 2017 (a) [55] | Pancreatic cancer | Case-control, cohort | Serum 25(OH)D | 12 | 893,168 | Incidence, mortality | 5 | 5 | RR = 1.02 (0.66–1.57) | HR = 0.81 (0.68–0.96) |
| Zhang 2017 (b) [55] | Pancreatic cancer | Case-control, cohort | Vit-D intake | 12 | 893,168 | Incidence | 2 | N/A | RR = 1.11 (0.67–1.86) | N/A |
| Zhang 2019 [56] | Total cancer | RCTs | Vit-D intake | 10 | 81,362 | Incidence, mortality | 10 | 7 | RR = 0.99 (0.94–1.03) | RR = 0.87 (0.79–0.95) |
| Zhang 2021 [57] | Liver cancer | Cohort | Serum 25(OH)D | 6 | 6357 | Incidence | 6 | N/A | HR = 0.53 (0.41–0.68) | N/A |
| Zhang 2022 [58] | Total cancer | RCTs | Vit-D intake | 12 | 72,669 | Incidence, mortality | 11 | 6 | RR = 0.99 (0.93–1.06) | RR = 0.96 (0.80–1.16) |
| Zhao 2016 [59] | Bladder cancer | Case-control, cohort | Serum 25(OH)D | 7 | 90,757 | Incidence | 7 | N/A | OR = 0.76 (0.66–1.87) | N/A |
| Zhou 2020 [60] | Breast cancer | RCTs | Vit-D intake | 8 | 72,275 | Incidence | 6 | N/A | RR = 1.04 (0.85–1.29) | N/A |
RCTs randomized controlled trials, HR hazard ratio, NOP number of studies, OR odds ratio, CI confidence interval, Vit-D Vitamin D, N/R not reported, RR risk ratio, N/A not available or data missing, x case-control studies, y prospective cohort studies, 25(OH)D 25-hidroksivitamin-D, * prospective studies, ** retrospective studies, *** cancer related mortality.