Findings

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Evidence found and GRADE certainty

4,721 questions · 19,640 findings · 2,039 reviews · Headline outcomes only

No studies found 3,754 · 19.1%GRADE not reported 1,273 · 6.5%Very low 4,859 · 24.7%Low 5,568 · 28.4%Moderate 3,240 · 16.5%High 946 · 4.8%

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Vitamin A vs placebo

Incidence of acute URTIs during the study period (the number of acute URTIs over a period of time) · children up to the age of 7 at risk of upper respiratory tract infection

Summary of findings table ‐ Vitamin A supplements showed no clear difference in incidence of acute URTIs during the study period (the number of… compared with placebo (low certainty).

1 finding from 1 review