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

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

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 Pre-eclampsia: OR 0.56 (95% CI 0.39 to 0.80), 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 0.56 [0.39, 0.80]
  9 studies · 3230 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 Head circumference: WMD 0.05 (95% CI -0.24 to 0.34), 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
  WMD 0.05 [-0.24, 0.34]
  2 studies · 840 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 Birth length: WMD 0.19 (95% CI -0.26 to 0.65), 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
  WMD 0.19 [-0.26, 0.65]
  2 studies · 840 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 Birth weight: WMD 130.9 (95% CI 75.1 to 186.7), statistically significant. Umbrella review outcome-level evidence grade: Probable.

• Vitamin D and multiple health outcomes: umbrella review of systematic reviews and meta-analyses of observational… 2014 All outcomes
  WMD 130.9 [75.1, 186.7]
  4 studies · 5541 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 Gestational diabetes: OR 0.67 (95% CI 0.53 to 0.85), 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 0.67 [0.53, 0.85]
  10 studies · 4112 participants
  GRADE not reported

Vitamin D plus calcium vs calcium

It is very uncertain whether vitamin D plus calcium changes healing of rickets (number) Definition: normal alkaline phosphatase… compared with calcium (very low certainty).

• Vitamin D, calcium or a combination of vitamin D and calcium for the treatment of nutritional rickets in children 2020 · Cochrane Headline outcomes only
  RR 1.17 [0.72, 1.9]
  2 studies · 140 participants
  Very low

Vitamin D plus calcium vs calcium

It is very uncertain whether vitamin D plus calcium changes morbidity (number) Definition: fractures compared with calcium (very low certainty).

• Vitamin D, calcium or a combination of vitamin D and calcium for the treatment of nutritional rickets in children 2020 · Cochrane Headline outcomes only
  RR 0.89 [0.06, 13.76]
  1 study · 72 participants
  Very low