The review found no eligible studies for this question.
It is very uncertain whether any‐treatment‐dose vitamin D (greater than 400 IU/day) changes withdrawals due to adverse events compared with supplemental‐dose vitamin D (less than 400 IU/day) (very low certainty).
The review found no eligible studies for this question.
It is very uncertain whether summary of findings table ‐ Vitamin B12 supplementation changes maternal anaemia compared with placebo/no vitamin B12 supplementation (very low certainty).
Summary of findings table ‐ Vitamin B12 supplementation showed no clear difference in low birthweight (< 2500 g) compared with placebo/no vitamin B12 supplementation (low certainty).
Summary of findings table ‐ Vitamin B12 supplementation showed no clear difference in preterm birth (< 37 weeks) compared with placebo/no vitamin B12 supplementation (low certainty).
The review found no eligible studies for this question.
The review found no eligible studies for this question.
High‐treatment‐dose vitamin D (greater than 1000 IU/day) showed no clear difference in clinical relapse at end of study (52 weeks) compared with low‐treatment‐dose vitamin D (400 IU/day to 1000 IU/day) (low certainty).
It is very uncertain whether high‐treatment‐dose vitamin D (greater than 1000 IU/day) changes withdrawals due to adverse events compared with low‐treatment‐dose vitamin D (400 IU/day to 1000 IU/day) (very low certainty).
Vitamin E (topical) led to higher improvement in mucositis compared with vitamin E (swallowed); GRADE not reported.
Vitamin E (topical) led to higher mucositis eradicated compared with vitamin E (swallowed); GRADE not reported.
Meta-analysis of observational studies (higher vs lower 25(OH)D) for Prostate cancer: OR 1.04 (95% CI 0.98 to 1.09), not statistically significant. Umbrella review outcome-level evidence grade: Substantial effect unlikely.
Meta-analysis of observational studies (higher vs lower 25(OH)D) for Type 2 diabetes: OR 0.63 (95% CI 0.56 to 0.69), statistically significant. Umbrella review outcome-level evidence grade: Suggestive.
Meta-analysis of observational studies (higher vs lower 25(OH)D) for Sporadic colorectal adenoma recurrence: OR 0.87 (95% CI 0.57 to 1.33), not statistically significant. Umbrella review outcome-level evidence grade: No conclusion.
Meta-analysis of observational studies (higher vs lower 25(OH)D) for Ischaemic heart disease: HR 0.72 (95% CI 0.65 to 0.81), statistically significant. Umbrella review outcome-level evidence grade: No conclusion.
Meta-analysis of observational studies (higher vs lower 25(OH)D) for Breast cancer (Premenopausal): RR 1.01 (95% CI 0.97 to 1.06), not statistically significant. Umbrella review outcome-level evidence grade: Substantial effect unlikely.