What do systematic reviews say?

Vitamin D plus calcium vs placebo or control

Vitamin D [D2, D3 or 25(OH)D] plus calcium showed no clear difference in persons with hypercalcaemia ‐ Vitamin D (D2, D3 or 25(OH)D) plus… compared with control or placebo (low certainty).

• Vitamin D and vitamin D analogues for preventing fractures in post‐menopausal women and older men 2014 · Cochrane Headline outcomes only
  RR 3.29 [0.37, 29.14]
  2 studies · 3853 participants
  Low

Vitamin D plus calcium vs placebo or control

Vitamin D [D2, D3 or 25(OH)D] plus calcium leads to higher persons with renal disease (calculi or insufficiency) ‐ Vitamin D… compared with control or placebo (high certainty).

• Vitamin D and vitamin D analogues for preventing fractures in post‐menopausal women and older men 2014 · Cochrane Headline outcomes only
  RR 1.17 [1.03, 1.34]
  2 studies · 39552 participants
  High

Vitamin D plus calcium vs placebo or control

Vitamin D [D2, D3 or 25(OH)D] plus calcium showed no clear difference in deaths ‐ Vitamin D (D2, D3, 25(OH)D) plus calcium (1 year estimate) compared with control or placebo (high certainty).

• Vitamin D and vitamin D analogues for preventing fractures in post‐menopausal women and older men 2014 · Cochrane Headline outcomes only
  RR 0.94 [0.87, 1.02]
  6 studies · 46794 participants
  High

Summary of findings: water‐soluble vitamin E vs control

The review found no eligible studies for this question.

• Vitamin E supplementation in people with cystic fibrosis 2020 · Cochrane Headline outcomes only
  no estimate extracted
  Studies not reported
  No studies found

Summary of findings: water‐soluble vitamin E vs control

Summary of findings: water‐soluble vitamin E may leads to higher vitamin E levels in serum: umol/L compared with control (low certainty).

• Vitamin E supplementation in people with cystic fibrosis 2020 · Cochrane Headline outcomes only
  MD 19.74 [13.48, 26]
  1 study · 45 participants
  Low

Summary of findings: water‐soluble vitamin E vs control

The review found no eligible studies for this question.

• Vitamin E supplementation in people with cystic fibrosis 2020 · Cochrane Headline outcomes only
  no estimate extracted
  Studies not reported
  No studies found

Summary of findings: water‐soluble vitamin E vs control

The review found no eligible studies for this question.

• Vitamin E supplementation in people with cystic fibrosis 2020 · 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

Staple food fortified with vitamin A plus other micronutrients vs no intervention

It is very uncertain whether staple food fortified with vitamin A plus other micronutrients changes subclinical vitamin A deficiency (serum/plasma retinol 0.70 μmol/L… compared with no intervention (very low certainty).

• Fortification of staple foods with vitamin A for vitamin A deficiency 2019 · Cochrane Headline outcomes only
  RR 0.71 [0.52, 0.98]
  2 studies · 318 participants
  Very low

Staple food fortified with vitamin A plus other micronutrients vs no intervention

The review found no eligible studies for this question.

• Fortification of staple foods with vitamin A for vitamin A deficiency 2019 · Cochrane Headline outcomes only
  no estimate extracted
  Studies not reported
  No studies found

Staple food fortified with vitamin A plus other micronutrients vs no intervention

The review found no eligible studies for this question.

• Fortification of staple foods with vitamin A for vitamin A deficiency 2019 · Cochrane Headline outcomes only
  no estimate extracted
  Studies not reported
  No studies found

Staple food fortified with vitamin A plus other micronutrients vs same unfortified staple foods

The review found no eligible studies for this question.

• Fortification of staple foods with vitamin A for vitamin A deficiency 2019 · Cochrane Headline outcomes only
  no estimate extracted
  Studies not reported
  No studies found

Staple food fortified with vitamin A plus other micronutrients vs same unfortified staple foods

Staple foods fortified with vitamin A plus other micronutrients probably leads to lower subclinical vitamin A deficiency (serum/plasma retinol 0.70 μmol/L… compared with same unfortified staple foods (moderate certainty).

• Fortification of staple foods with vitamin A for vitamin A deficiency 2019 · Cochrane Headline outcomes only
  RR 0.27 [0.16, 0.49]
  3 studies · 923 participants
  Moderate

Staple food fortified with vitamin A plus other micronutrients vs same unfortified staple foods

The review found no eligible studies for this question.

• Fortification of staple foods with vitamin A for vitamin A deficiency 2019 · Cochrane Headline outcomes only
  no estimate extracted
  Studies not reported
  No studies found