What do systematic reviews say?

Vitamin D vs placebo or no treatment

It is very uncertain whether vitamin D changes acute graft rejection compared with placebo or no treatment (very low certainty).

• Interventions for preventing bone disease in kidney transplant recipients 2019 · Cochrane Headline outcomes only
  RR 0.98 [0.52, 1.86]
  5 studies · 385 participants
  Very low

Vitamin D vs placebo

It is very uncertain whether vitamin D changes mortality compared with placebo (very low certainty).

• Micronutrient supplementation in adults with HIV infection 2017 · Cochrane Headline outcomes only
  RR 1.15 [0.65, 2.02]
  1 study · 131 participants
  Very low

Vitamin D vs placebo

• Micronutrient supplementation in adults with HIV infection 2017 · Cochrane Headline outcomes only
  no estimate extracted
  0 studies · 0 participants
  GRADE not reported

Vitamin D vs placebo

• Micronutrient supplementation in adults with HIV infection 2017 · Cochrane Headline outcomes only
  no estimate extracted
  4 studies · 288 participants
  Low

Vitamin D vs placebo

• Micronutrient supplementation in adults with HIV infection 2017 · Cochrane Headline outcomes only
  no estimate extracted
  1 study · 28 participants
  Very low

Vitamin A vs placebo

• Micronutrient supplementation in adults with HIV infection 2017 · Cochrane Headline outcomes only
  no estimate extracted
  0 studies · 0 participants
  GRADE not reported

Vitamin A vs placebo

• Micronutrient supplementation in adults with HIV infection 2017 · Cochrane Headline outcomes only
  no estimate extracted
  0 studies · 0 participants
  GRADE not reported

Vitamin A vs placebo

• Micronutrient supplementation in adults with HIV infection 2017 · Cochrane Headline outcomes only
  no estimate extracted
  2 studies · 464 participants
  Low

Vitamin A vs placebo

• Micronutrient supplementation in adults with HIV infection 2017 · Cochrane Headline outcomes only
  no estimate extracted
  3 studies · 495 participants
  Low

SoF vitamin E vs placebo

• Non‐hormonal interventions for hot flushes in women with a history of breast cancer 2010 · Cochrane Headline outcomes only
  no estimate extracted
  1 study · 104 participants
  High

SoF vitamin E vs placebo

• Non‐hormonal interventions for hot flushes in women with a history of breast cancer 2010 · Cochrane Headline outcomes only
  no estimate extracted
  1 study · 104 participants
  High

Vitamin A plus iron plus folate vs iron plus folate

The review found no eligible studies for this question.

• Vitamin supplementation for preventing miscarriage 2016 · Cochrane Headline outcomes only
  no estimate extracted
  Studies not reported
  No studies found

Any intermittent iron regimen (with or without other vitamins and minerals) vs daily regimen (with same vitamins and minerals)‐maternal outcomes

Any intermittent iron regimen (with or without other vitamins and… showed no clear difference in low birthweight (less than 2500 g) compared with daily regimen (with same vitamins and minerals)‐infant outcomes (low certainty).

• Intermittent oral iron supplementation during pregnancy 2015 · Cochrane Headline outcomes only
  RR 0.82 [0.55, 1.22]
  8 studies · 1898 participants
  Low

Any intermittent iron regimen (with or without other vitamins and minerals) vs daily regimen (with same vitamins and minerals)‐maternal outcomes

It is very uncertain whether any intermittent iron regimen (with or without other vitamins and… changes side effects (any reported throughout intervention period) compared with daily regimen (with same vitamins and minerals)‐maternal outcomes (very low certainty).

• Intermittent oral iron supplementation during pregnancy 2015 · Cochrane Headline outcomes only
  RR 0.56 [0.37, 0.84]
  11 studies · 1777 participants
  Very low

Any intermittent iron regimen (with or without other vitamins and minerals) vs daily regimen (with same vitamins and minerals)‐maternal outcomes

• Intermittent oral iron supplementation during pregnancy 2015 · Cochrane Headline outcomes only
  no estimate extracted
  6 studies · 1240 participants
  Very low

Any intermittent iron regimen (with or without other vitamins and minerals) vs daily regimen (with same vitamins and minerals)‐maternal outcomes

Any intermittent iron regimen (with or without other vitamins and… led to lower maternal clinical malaria or other infection in pregnancy compared with daily regimen (with same vitamins and minerals)‐maternal outcomes; GRADE not reported.

• Intermittent oral iron supplementation during pregnancy 2015 · Cochrane Headline outcomes only
  RR 0 [0, 0]
  0 studies · 0 participants
  GRADE not reported

Any intermittent iron regimen (with or without other vitamins and minerals) vs daily regimen (with same vitamins and minerals)‐maternal outcomes

Any intermittent iron regimen (with or without other vitamins and… showed no clear difference in birthweight (g) compared with daily regimen (with same vitamins and minerals)‐infant outcomes (low certainty).

• Intermittent oral iron supplementation during pregnancy 2015 · Cochrane Headline outcomes only
  MD 5.13
  9 studies · 1939 participants
  Low

Any intermittent iron regimen (with or without other vitamins and minerals) vs daily regimen (with same vitamins and minerals)‐maternal outcomes

Any intermittent iron regimen (with or without other vitamins and… showed no clear difference in premature birth (less than 37 weeks of gestation) compared with daily regimen (with same vitamins and minerals)‐infant outcomes (low certainty).

• Intermittent oral iron supplementation during pregnancy 2015 · Cochrane Headline outcomes only
  RR 1.03 [0.76, 1.39]
  5 studies · 1177 participants
  Low

Any intermittent iron regimen (with or without other vitamins and minerals) vs daily regimen (with same vitamins and minerals)‐maternal outcomes

It is very uncertain whether any intermittent iron regimen (with or without other vitamins and… changes neonatal death (within 28 days after delivery) compared with daily regimen (with same vitamins and minerals)‐infant outcomes (very low certainty).

• Intermittent oral iron supplementation during pregnancy 2015 · Cochrane Headline outcomes only
  RR 0.49 [0.04, 5.42]
  1 study · 795 participants
  Very low

Any intermittent iron regimen (with or without other vitamins and minerals) vs daily regimen (with same vitamins and minerals)‐maternal outcomes

• Intermittent oral iron supplementation during pregnancy 2015 · Cochrane Headline outcomes only
  no estimate extracted
  0 studies · 0 participants
  GRADE not reported