What do systematic reviews say?

Vitamin D vs placebo or no intervention

The review found no eligible studies for this question.

• Vitamin D supplementation for prevention of cancer in adults 2014 · Cochrane Headline outcomes only
  no estimate extracted
  Studies not reported
  No studies found

Vitamin D plus calcium vs vitamin D

The review found no eligible studies for this question.

• Vitamin D, calcium or a combination of vitamin D and calcium for the treatment of nutritional rickets in children 2020 · Cochrane Headline outcomes only
  no estimate extracted
  Studies not reported
  No studies found

Vitamin D vs placebo or no intervention

• Vitamin D supplementation for chronic liver diseases in adults 2021 · Cochrane Headline outcomes only
  no estimate extracted
  0 studies · 0 participants
  GRADE not reported

Vitamin D plus calcium vs calcium

The review found no eligible studies for this question.

• Vitamin D, calcium or a combination of vitamin D and calcium for the treatment of nutritional rickets in children 2020 · Cochrane Headline outcomes only
  no estimate extracted
  Studies not reported
  No studies found

Vitamin C vs placebo

• Vitamin C for asthma and exercise‐induced bronchoconstriction 2013 · Cochrane Headline outcomes only
  no estimate extracted
  1 study · 201 participants
  Low

Vitamin C vs placebo

The review found no eligible studies for this question.

• Vitamin C for asthma and exercise‐induced bronchoconstriction 2013 · Cochrane Headline outcomes only
  no estimate extracted
  Studies not reported
  No studies found

Oral vs intramuscular vitamin B12

The review found no eligible studies for this question.

• Oral vitamin B₁₂ versus intramuscular vitamin B₁₂ for vitamin B₁₂ deficiency 2018 · Cochrane Headline outcomes only
  no estimate extracted
  Studies not reported
  No studies found

Idraparinux secondary prophylaxis vs vitamin K antagonist secondary prophylaxis

The review found no eligible studies for this question.

• Anticoagulation for the long‐term treatment of venous thromboembolism in people with cancer 2018 · Cochrane Headline outcomes only
  no estimate extracted
  Studies not reported
  No studies found

Intervention not reported

The review found no eligible studies for this question.

• Vitamin D, calcium or a combination of vitamin D and calcium for the treatment of nutritional rickets in children 2020 · Cochrane Headline outcomes only
  no estimate extracted
  Studies not reported
  No studies found

Intervention not reported

The review found no eligible studies for this question.

• Vitamins C and E for asthma and exercise‐induced bronchoconstriction 2014 · Cochrane Headline outcomes only
  no estimate extracted
  Studies not reported
  No studies found

Intervention not reported

The review found no eligible studies for this question.

• Vitamins C and E for asthma and exercise‐induced bronchoconstriction 2014 · Cochrane Headline outcomes only
  no estimate extracted
  Studies not reported
  No studies found

Intervention not reported

• Vitamin D supplementation for prevention of mortality in adults 2014 · Cochrane Headline outcomes only
  no estimate extracted
  1 study · 105 participants
  GRADE not reported