What do systematic reviews say?

Vitamin D plus calcium vs placebo

• Calcium and vitamin D for increasing bone mineral density in premenopausal women 2023 · Cochrane Headline outcomes only
  no estimate extracted
  1 study · 408 participants
  Moderate

Vitamin D plus calcium vs placebo

• Calcium and vitamin D for increasing bone mineral density in premenopausal women 2023 · Cochrane Headline outcomes only
  no estimate extracted
  1 study · 76 participants
  Moderate

Vitamin D plus calcium vs placebo

The review found no eligible studies for this question.

• Calcium and vitamin D for increasing bone mineral density in premenopausal women 2023 · Cochrane Headline outcomes only
  no estimate extracted
  Studies not reported
  No studies found

Vitamin D plus calcium vs placebo

The review found no eligible studies for this question.

• Calcium and vitamin D for increasing bone mineral density in premenopausal women 2023 · Cochrane Headline outcomes only
  no estimate extracted
  Studies not reported
  No studies found

Vitamin D plus calcium vs placebo

The review found no eligible studies for this question.

• Calcium and vitamin D for increasing bone mineral density in premenopausal women 2023 · Cochrane Headline outcomes only
  no estimate extracted
  Studies not reported
  No studies found

Vitamin D plus calcium vs placebo

Calcium and vitamin D showed no clear difference in withdrawals from the study for any reason compared with placebo (low certainty).

• Calcium and vitamin D for increasing bone mineral density in premenopausal women 2023 · Cochrane Headline outcomes only
  RR 0.82 [0.29, 2.35]
  2 studies · 541 participants
  Low

Vitamin D plus calcium vs placebo

The review found no eligible studies for this question.

• Calcium and vitamin D for increasing bone mineral density in premenopausal women 2023 · Cochrane Headline outcomes only
  no estimate extracted
  Studies not reported
  No studies found

Vitamin E + vitamin C vs placebo

The review found no eligible studies for this question.

• Vitamin and mineral supplementation for preventing dementia or delaying cognitive decline in people with mild… 2018 · Cochrane Headline outcomes only
  no estimate extracted
  Studies not reported
  No studies found

Vitamin E + vitamin C vs placebo

• Vitamin and mineral supplementation for preventing dementia or delaying cognitive decline in people with mild… 2018 · Cochrane Headline outcomes only
  no estimate extracted
  1 study · 256 participants
  Very low

Vitamin E + vitamin C vs placebo

The review found no eligible studies for this question.

• Vitamin and mineral supplementation for preventing dementia or delaying cognitive decline in people with mild… 2018 · Cochrane Headline outcomes only
  no estimate extracted
  Studies not reported
  No studies found

Vitamin E + vitamin C vs placebo

The review found no eligible studies for this question.

• Vitamin and mineral supplementation for preventing dementia or delaying cognitive decline in people with mild… 2018 · Cochrane Headline outcomes only
  no estimate extracted
  Studies not reported
  No studies found

Vitamin E + vitamin C vs placebo

The review found no eligible studies for this question.

• Vitamin and mineral supplementation for preventing dementia or delaying cognitive decline in people with mild… 2018 · Cochrane Headline outcomes only
  no estimate extracted
  Studies not reported
  No studies found

Vitamin E + vitamin C vs placebo

The review found no eligible studies for this question.

• Vitamin and mineral supplementation for preventing dementia or delaying cognitive decline in people with mild… 2018 · Cochrane Headline outcomes only
  no estimate extracted
  Studies not reported
  No studies found

Vitamin E + vitamin C vs placebo

The review found no eligible studies for this question.

• Vitamin and mineral supplementation for preventing dementia or delaying cognitive decline in people with mild… 2018 · Cochrane Headline outcomes only
  no estimate extracted
  Studies not reported
  No studies found

Higher circulating 1,25-dihydroxyvitamin D (1,25(OH)2D) concentration vs Lower circulating 1,25-dihydroxyvitamin D (1,25(OH)2D) concentration

Meta-analysis of observational studies (higher vs lower 1,25(OH)2D) for Colorectal cancer: OR 1.01 (95% CI 0.59 to 1.73), not statistically significant. Umbrella review outcome-level evidence grade: Suggestive.

• Vitamin D and multiple health outcomes: umbrella review of systematic reviews and meta-analyses of observational… 2014 All outcomes
  OR 1.01 [0.59, 1.73]
  4 studies
  GRADE not reported

Higher circulating 1,25-dihydroxyvitamin D (1,25(OH)2D) concentration vs Lower circulating 1,25-dihydroxyvitamin D (1,25(OH)2D) concentration

Meta-analysis of observational studies (higher vs lower 1,25(OH)2D) for Breast cancer: OR 0.99 (95% CI 0.68 to 1.44), not statistically significant. Umbrella review outcome-level evidence grade: No conclusion.

• Vitamin D and multiple health outcomes: umbrella review of systematic reviews and meta-analyses of observational… 2014 All outcomes
  OR 0.99 [0.68, 1.44]
  3 studies · 3627 participants
  GRADE not reported

Higher circulating 1,25-dihydroxyvitamin D (1,25(OH)2D) concentration vs Lower circulating 1,25-dihydroxyvitamin D (1,25(OH)2D) concentration

Meta-analysis of observational studies (higher vs lower 1,25(OH)2D) for Colon cancer: OR 0.88 (95% CI 0.57 to 1.35), not statistically significant. Umbrella review outcome-level evidence grade: No conclusion.

• Vitamin D and multiple health outcomes: umbrella review of systematic reviews and meta-analyses of observational… 2014 All outcomes
  OR 0.88 [0.57, 1.35]
  4 studies
  GRADE not reported

Higher circulating 1,25-dihydroxyvitamin D (1,25(OH)2D) concentration vs Lower circulating 1,25-dihydroxyvitamin D (1,25(OH)2D) concentration

Meta-analysis of observational studies (higher vs lower 1,25(OH)2D) for Aggressive prostate cancer: OR 0.75 (95% CI 0.48 to 1.17), not statistically significant. Umbrella review outcome-level evidence grade: Substantial effect unlikely.

• Vitamin D and multiple health outcomes: umbrella review of systematic reviews and meta-analyses of observational… 2014 All outcomes
  OR 0.75 [0.48, 1.17]
  2 studies · 1488 participants
  GRADE not reported

Higher circulating 1,25-dihydroxyvitamin D (1,25(OH)2D) concentration vs Lower circulating 1,25-dihydroxyvitamin D (1,25(OH)2D) concentration

Meta-analysis of observational studies (higher vs lower 1,25(OH)2D) for Prostate cancer: OR 0.99 (95% CI 0.87 to 1.14), not statistically significant. Umbrella review outcome-level evidence grade: Substantial effect unlikely.

• Vitamin D and multiple health outcomes: umbrella review of systematic reviews and meta-analyses of observational… 2014 All outcomes
  OR 0.99 [0.87, 1.14]
  7 studies · 3640 participants
  GRADE not reported

Higher maternal circulating 25-hydroxyvitamin D (25(OH)D) concentration vs Lower maternal circulating 25-hydroxyvitamin D (25(OH)D) concentration

Meta-analysis of observational studies (higher vs lower maternal 25(OH)D) for Small for gestational age: OR 0.54 (95% CI 0.44 to 0.67), statistically significant. Umbrella review outcome-level evidence grade: Suggestive.

• Vitamin D and multiple health outcomes: umbrella review of systematic reviews and meta-analyses of observational… 2014 All outcomes
  OR 0.54 [0.44, 0.67]
  6 studies · 6851 participants
  GRADE not reported