Table 2.
Associations between Vitamin E intake and cancer outcomes.
| Outcome | Category | References | No. of cases/ total | No. of studies | Cohort | Case-control | RCT | Meta metric | Effects model | Estimates | 95%CI | I2; Q test P value | Egger test P value |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Significant associations | |||||||||||||
| Breast Cancer | total intake vitamin E | Fulan et al. (26) | NA/ NA | 43 | 14 | 26 | 3 | OR | Random | 0.89 | 0.81,0.97 | 68.3%; NA | 0.180 |
| Breast Cancer | dietary vitamin E | Fulan et al. (26) | NA/ NA | 29 | 9 | 20 | 0 | OR | Random | 0.82 | 0.73,0.91 | 72.1%; NA | 0.150 |
| Lung Cancer | dietary vitamin E | Zhu et al. (27) | 4,164/ 435,532 | 9 | 9 | 0 | 0 | RR | Fixed | 0.84 | 0.76,0.93 | 41.1%; 0.075 | 0.246 |
| Esophageal Cancer | dietary vitamin E | Cui et al. (28) | 3,013/ 11,384 | 12 | 1 | 11 | 0 | RR | Random | 0.47 | 0.36,0.60 | 67.5%; < 0.001 | 0.008 |
| Gastric Cancer | dietary vitamin E | Kong et al. (29) | 3,299/ 634,667 | 8 | 3 | 5 | 0 | RR | Random | 0.76 | 0.67,0.85 | 43.0%; 0.090 | 0.254 |
| Pancreatic Cancer | dietary vitamin E | Chen et al. (30) | 3,070/ 230,206 | 11 | 4 | 7 | 0 | OR | Fixed | 0.70 | 0.62,0.81 | 0.0%; 0.455 | 0.596 |
| Kidney Cancer | dietary vitamin E | Shen et al. (31) | 1,213/ 450,463 | 6 | 6 | 0 | 0 | RR | NA | 0.88 | 0.72,1.08 | 49.2%; 0.023 | 0.928 |
| Bladder Cancer | dietary vitamin E | Lin et al. (32) | 3,265/ 575,601 | 11 | 8 | 0 | 3 | RR | Fixed | 0.89 | 0.78,1.00 | 19.9%; 0.254 | 0.707 |
| Cervical Neoplasm | total intake vitamin E | Hu et al. (33) | NA/ 5,301 | 6 | 0 | 6 | 0 | OR | Random | 0.68 | 0.49,0.94 | 70.0%; 0.005 | 0.530 |
| Non-significant associations | |||||||||||||
| Glioma | dietary vitamin E | Qin et al. (34) | 3180/ NA | 12 | 2 | 10 | 0 | RR | Random | 0.88 | 0.69,1.12 | 64.9%; 0.001 | NA |
| Thyroid Cancer | dietary vitamin E | Zhang et al. (35) | 1,021/ 15,005 | 4 | 0 | 3 | 1 | OR | NA | 1.50 | 0.90,2.60 | NA; NA | NA |
| Breast Cancer | vitamin E supplements | Fulan et al. (26) | NA | 12 | NA | NA | NA | OR | Random | 0.98 | 0.92,1.04 | 0.0%; NA | 0.010 |
| Breast Cancer | combined intake vitamin E | Fulan et al. (26) | NA | 14 | NA | NA | NA | OR | Random | 0.82 | 0.73,0.91 | 44.2%; NA | 1.000 |
| Colorectal Cancer | dietary vitamin E | Liu (36) | NA | 13 | NA | NA | NA | RR | Random | 0.94 | 0.82,1.07 | 10.3%; NA | 0.018 |
| Kidney Cancer | dietary vitamin E | Shen et al. (31) | 5,731/ 20,543 | 7 | 0 | 7 | 0 | RR | NA | 0.78 | 0.62,0.97 | 49.2%; 0.023 | 0.928 |
| Endometrial Cancer | dietary vitamin E | Bandera et al. (37) | 2,800/ 3,873 | 6 | 0 | 6 | 0 | OR | Random | 0.91 | 0.84,0.99 | 0.0%; 0.450 | NA |
| Ovarian Cancer | total intake vitamin E | Leng et al. (38) | 4,597/ 440,532 | 14 | 5 | 9 | 0 | RR | Random | 0.95 | 0.78,1.16 | 53.2%; 0.019 | NA |
| NHL | total intake vitamin E | Psaltopoulou et al. (39) | 3,840/ 189,522 | 4 | 4 | 0 | 0 | RR | Random | 0.94 | 0.65,1.36 | 0.0%; 0.889 | NA |
| Total Cancer | dietary vitamin E | Aune et al. (40) | 5,718/ 169,236 | 5 | NA | NA | NA | RR | Random | 0.97 | 0.93,1.02 | 61.0 %; 0.030 | 0.070 |
| Cancer Mortality | dietary vitamin E | Schwingshackl et al. (41) | 3,605/ 279,666 | 3 | NA | NA | NA | RR | Fixed | 1.00 | 0.79,1.28 | 45.0%; NA | NA |
CI, confidence interval; RCT, randomized controlled trial; RR, relative risk; OR, odds ratio; NA, not available; NHL, non-Hodgkin lymphoma.