Findings

What do systematic reviews say?

6 questions · 6 findings · 3 reviews

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No studies found 5 · 83.3%GRADE not reported 0 · 0%Very low 1 · 16.7%Low 0 · 0%Moderate 0 · 0%High 0 · 0%

Vitamin C vs placebo

Adverse effects · children under 5 years of age

The review found no eligible studies for this question.

1 finding from 1 review

Vitamin C supplementation for prevention and treatment of pneumonia 2021 · Cochrane Headline outcomes only
no estimate extracted
Studies not reported
No studies found

Vitamin C vs placebo

Adverse effects (urticaria) Defined as participants reporting urticaria (hives) Dose: 2 g per day · school‐aged children (6 to 15 years) and marine corps recruits (mean age 18.5 years)

It is very uncertain whether vitamin C changes adverse effects (urticaria) Defined as participants reporting… compared with placebo (very low certainty).

1 finding from 1 review

Vitamin C supplementation for prevention and treatment of pneumonia 2021 · Cochrane Headline outcomes only
RR 3.11 [0.13, 76.03]
1 study · 674 participants
Very low

Staple foods fortified with vitamin A vs same unfortified staple foods

Any adverse effects (e.g. hypervitaminosis A, as defined by the trialists) · general population over 2 years of age

The review found no eligible studies for this question.

1 finding from 1 review

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

Any adverse effects (e.g. hypervitaminosis A, as defined by the trialists) · general population over 2 years of age

The review found no eligible studies for this question.

1 finding from 1 review

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

Any adverse effects (e.g. hypervitaminosis A, as defined by the trialists) · general population over 2 years of age

The review found no eligible studies for this question.

1 finding from 1 review

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

Provision of maize flour or maize flour products fortified with iron plus other vitamins and minerals vs unfortified maize flours or maize flour products

Any adverse effects (including constipation, nausea, vomiting, heartburn or diarrhoea, as measured by trialists) · general population older than 2 years of age (including pregnant women), in Kenya and Mexico

The review found no eligible studies for this question.

1 finding from 1 review

Fortification of maize flour with iron for controlling anaemia and iron deficiency in populations 2018 · Cochrane Headline outcomes only
no estimate extracted
Studies not reported
No studies found