Vitamin D vs placebo or no intervention
Maternal adverse event: hypercalcaemia · pregnant women and their infants..
1 finding from 1 review
- no estimate extracted1 study · 1134 participantsLow
Findings
What do systematic reviews say?
780 questions · 834 findings · 76 reviews
No studies found 187 · 22.4%GRADE not reported 164 · 19.7%Very low 144 · 17.3%Low 172 · 20.6%Moderate 105 · 12.6%High 62 · 7.4%
Vitamin D vs placebo or no intervention
Preterm birth · pregnant women and their infants..
Vitamin D supplementation showed no clear difference in preterm birth (less than 37 weeks' gestation) compared with placebo or no intervention (low certainty).
1 finding from 1 review
- RR 0.66 [0.34, 1.3]7 studies · 1640 participantsLow
Vitamin D vs placebo or no intervention
Low birthweight · pregnant women and their infants..
Vitamin D supplementation probably leads to lower low birthweight (less than 2500 g) compared with placebo or no intervention (moderate certainty).
1 finding from 1 review
- RR 0.55 [0.35, 0.87]5 studies · 697 participantsModerate
Vitamin C vs placebo
Major cardiovascular event Physicians · middle‐aged US male physicians
Vitamin C supplementation showed no clear difference in major cardiovascular event Physicians compared with placebo (low certainty).
1 finding from 1 review
- Vitamin C supplementation for the primary prevention of cardiovascular disease 2017 · Cochrane Headline outcomes onlyHR 0.99 [0.89, 1.1]1 study · 14641 participantsLow
Vitamin C vs placebo
Cardiovascular mortality Physicians · middle‐aged US male physicians
It is very uncertain whether vitamin C supplementation changes cardiovascular mortality Physicians compared with placebo (very low certainty).
1 finding from 1 review
- Vitamin C supplementation for the primary prevention of cardiovascular disease 2017 · Cochrane Headline outcomes onlyHR 1.02 [0.85, 1.22]1 study · 14641 participantsVery low
Vitamin C vs placebo
All‐cause mortality Physicians · middle‐aged US male physicians
It is very uncertain whether vitamin C supplementation changes all‐cause mortality Physicians compared with placebo (very low certainty).
1 finding from 1 review
- Vitamin C supplementation for the primary prevention of cardiovascular disease 2017 · Cochrane Headline outcomes onlyHR 1.07 [0.97, 1.18]1 study · 14641 participantsVery low
Vitamin C vs placebo
Fatal or nonfatal myocardial infarction · middle‐aged US male physicians
Vitamin C supplementation showed no clear difference in total myocardial infarction (fatal and non‐fatal) Physicians compared with placebo (low certainty).
1 finding from 1 review
- Vitamin C supplementation for the primary prevention of cardiovascular disease 2017 · Cochrane Headline outcomes onlyHR 1.04 [0.87, 1.24]1 study · 14641 participantsLow
Vitamin C vs placebo
Stroke · middle‐aged US male physicians
Vitamin C supplementation showed no clear difference in total stroke (fatal and non‐fatal) Physicians compared with placebo (low certainty).
1 finding from 1 review
- Vitamin C supplementation for the primary prevention of cardiovascular disease 2017 · Cochrane Headline outcomes onlyHR 0.89 [0.74, 1.07]1 study · 14641 participantsLow
Vitamin C vs placebo
Self‐reported CABG/PTCA Participant self‐reports · middle‐aged US male physicians
Vitamin C supplementation showed no clear difference in self‐reported CABG/PTCA Participant self‐reports compared with placebo (low certainty).
1 finding from 1 review
- Vitamin C supplementation for the primary prevention of cardiovascular disease 2017 · Cochrane Headline outcomes onlyHR 0.96 [0.86, 1.07]1 study · 14641 participantsLow
Vitamin C vs placebo
Self‐reported angina Participant self‐reports · middle‐aged US male physicians
Vitamin C supplementation showed no clear difference in self‐reported angina Participant self‐reports compared with placebo (low certainty).
1 finding from 1 review
- Vitamin C supplementation for the primary prevention of cardiovascular disease 2017 · Cochrane Headline outcomes onlyHR 0.93 [0.84, 1.03]1 study · 14641 participantsLow
Vitamin D vs placebo or control
Fasting blood glucose (mg/dL) · Adults with diabetes
Meta-analysis of randomised trials of vitamin D supplementation for Fasting glucose (Diabetes patients with normal glucose tolerance): WMD 0.01 (95% CI -0.21 to 0.23), not statistically significant. Umbrella review outcome-level evidence grade: Substantial effect unlikely.
2 findings from 1 review
- Vitamin D and multiple health outcomes: umbrella review of systematic reviews and meta-analyses of observational… 2014 All outcomesDiabetes patients with normal glucose toleranceWMD 0.01 [-0.21, 0.23]Studies not reportedGRADE not reported
- Vitamin D and multiple health outcomes: umbrella review of systematic reviews and meta-analyses of observational… 2014 All outcomesDiabetes patients with abnormal glucose toleranceWMD -0.3 [-0.9, 0.3]Studies not reportedGRADE not reported
Vitamin D vs placebo or control
Femoral neck bone mineral density (FN-BMD) · Older or community-dwelling adults
Meta-analysis of randomised trials of vitamin D supplementation for Bone mineral density in femoral neck, Community-dwelling adults: WMD 1.10 (95% CI 0.40 to 1.90), statistically significant. Umbrella review outcome-level evidence grade: Suggestive.
1 finding from 1 review
- Vitamin D and multiple health outcomes: umbrella review of systematic reviews and meta-analyses of observational… 2014 All outcomesCommunity-dwelling adultsWMD 1.10 [0.40, 1.90]8 studiesGRADE not reported
Vitamin D vs placebo or control
Lumbar spine bone mineral density (BMD) · Older or community-dwelling adults
Meta-analysis of randomised trials of vitamin D supplementation for Bone mineral density in lumbar spine, Community-dwelling adults: WMD 0.10 (95% CI -0.60 to 0.70), not statistically significant. Umbrella review outcome-level evidence grade: Substantial effect unlikely.
1 finding from 1 review
- Vitamin D and multiple health outcomes: umbrella review of systematic reviews and meta-analyses of observational… 2014 All outcomesCommunity-dwelling adultsWMD 0.10 [-0.60, 0.70]7 studiesGRADE not reported
Vitamin D vs placebo or control
Non‐vertebral fractures · Older or community-dwelling adults
Meta-analysis of randomised trials of vitamin D supplementation for Fractures: non-vertebral, People aged >65 years: RR 0.79 (95% CI 0.63 to 0.99), statistically significant. Umbrella review outcome-level evidence grade: Suggestive.
1 finding from 1 review
- Vitamin D and multiple health outcomes: umbrella review of systematic reviews and meta-analyses of observational… 2014 All outcomesPeople aged >65 yearsRR 0.79 [0.63, 0.99]5 studies · 7130 participantsGRADE not reported
Vitamin D vs placebo or control
Muscle strength · Older or community-dwelling adults
Meta-analysis of randomised trials of vitamin D supplementation for Performance measures: muscle strength, Older adults: SMD -0.19 (95% CI -0.35 to -0.02), statistically significant. Umbrella review outcome-level evidence grade: Suggestive.
1 finding from 1 review
- Vitamin D and multiple health outcomes: umbrella review of systematic reviews and meta-analyses of observational… 2014 All outcomesOlder adultsSMD -0.19 [-0.35, -0.02]3 studiesGRADE not reported
Vitamin D vs placebo or control
Fractures: non-vertebral, non-hip · Older or community-dwelling adults
Meta-analysis of randomised trials of vitamin D supplementation for Fractures: non-vertebral, non-hip, Older women: OR 0.69 (95% CI 0.21 to 1.66), not statistically significant. Umbrella review outcome-level evidence grade: No conclusion.
1 finding from 1 review
- Vitamin D and multiple health outcomes: umbrella review of systematic reviews and meta-analyses of observational… 2014 All outcomesOlder womenOR 0.69 [0.21, 1.66]2 studiesGRADE not reported
Vitamin D vs placebo or control
Diastolic blood pressure · Adults (general population)
Meta-analysis of randomised trials of vitamin D supplementation for Diastolic blood pressure: WMD -0.03 (95% CI -1.98 to 1.92), not statistically significant. Umbrella review outcome-level evidence grade: Suggestive.
1 finding from 1 review
- Vitamin D and multiple health outcomes: umbrella review of systematic reviews and meta-analyses of observational… 2014 All outcomesWMD -0.03 [-1.98, 1.92]3 studiesGRADE not reported
Vitamin D vs placebo or control
Gestational age at birth (weeks) · pregnant women
Meta-analysis of randomised trials of vitamin D supplementation for Mean gestational age at delivery: WMD 0.17 (95% CI -0.16 to 0.51), not statistically significant. Umbrella review outcome-level evidence grade: No conclusion.
1 finding from 1 review
- Vitamin D and multiple health outcomes: umbrella review of systematic reviews and meta-analyses of observational… 2014 All outcomesWMD 0.17 [-0.16, 0.51]2 studiesGRADE not reported
Vitamin D vs placebo or control
Small‐for‐gestational age · pregnant women
Meta-analysis of randomised trials of vitamin D supplementation for Small for gestational age: RR 0.67 (95% CI 0.40 to 1.11), not statistically significant. Umbrella review outcome-level evidence grade: Suggestive.
1 finding from 1 review
- Vitamin D and multiple health outcomes: umbrella review of systematic reviews and meta-analyses of observational… 2014 All outcomesRR 0.67 [0.40, 1.11]2 studies · 305 participantsGRADE not reported
Vitamin D vs placebo or control
Bone mineral density in forearm · children
Meta-analysis of randomised trials of vitamin D supplementation for Bone mineral density in forearm, Healthy children: SMD 0.04 (95% CI -0.36 to 0.45), not statistically significant. Umbrella review outcome-level evidence grade: Substantial effect unlikely.
1 finding from 1 review
- Vitamin D and multiple health outcomes: umbrella review of systematic reviews and meta-analyses of observational… 2014 All outcomesHealthy childrenSMD 0.04 [-0.36, 0.45]3 studiesGRADE not reported