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Evidence found and GRADE certainty

780 questions · 834 findings · 76 reviews

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No studies found 187 · 22.4%GRADE not reported 164 · 19.7%Very low 144 · 17.3%Low 172 · 20.6%Moderate 105 · 12.6%High 62 · 7.4%

Vitamin D vs placebo or no intervention

Cancer occurrence in trials using vitamin D₃ (cholecalciferol) · healthy participants or recruited among the general population; individuals diagnosed with a specific disease in a stable phase or with…

Vitamin D showed no clear difference in cancer occurrence in trials using vitamin D₃ (cholecalciferol) compared with placebo or no intervention (moderate certainty).

1 finding from 1 review

Vitamin D vs placebo or no intervention

Cancer mortality in trials using vitamin D3 (cholecalciferol) ( · healthy participants or recruited among the general population; individuals diagnosed with a specific disease in a stable phase or with…

Vitamin D may leads to lower cancer mortality in trials using vitamin D₃(cholecalciferol) compared with placebo or no intervention (low certainty).

1 finding from 1 review

Vitamin D vs placebo or no intervention

Adverse events ‐ Nephrolithiasis in trials using vitamin D3 combined with calcium · healthy participants or recruited among the general population; individuals diagnosed with a specific disease in a stable phase or with…

Vitamin D may leads to higher adverse events: nephrolithiasis in trials using vitamin… compared with placebo or no intervention (low certainty).

1 finding from 1 review

Neonatal vitamin A supplementation vs control

Vitamin A deficiency · mortality and morbidity in term neonates

Neonatal vitamin A supplementation showed no clear difference in vitamin A deficiency (serum retinol < 0.70 micromol/L) at 6 weeks of… compared with control (high certainty).

2 findings from 1 review

Staple foods fortified with vitamin A vs same unfortified staple foods

Subclinical vitamin A deficiency (serum/plasma retinol 70 μmol/L or less) · general population over 2 years of age

It is very uncertain whether staple foods fortified with vitamin A changes subclinical vitamin A deficiency (serum/plasma retinol 70 μmol/L or… compared with same unfortified staple foods (very low certainty).

1 finding from 1 review

Staple foods fortified with vitamin A vs same unfortified staple foods

Clinical vitamin A deficiency (as defined by night blindness) · general population over 2 years of age

It is very uncertain whether staple foods fortified with vitamin A changes clinical vitamin A deficiency (defined as night blindness) compared with same unfortified staple foods (very low certainty).

1 finding from 1 review

Vitamin A vs placebo

Incidence: lung cancer · healthy people and healthy male physicians

Vitamin A showed no clear difference in incidence: lung cancer compared with placebo (high certainty).

1 finding from 1 review

Vitamin A vs placebo

Mortality: lung cancer · healthy people and healthy male physicians

Vitamin A showed no clear difference in mortality: lung cancer compared with placebo (high certainty).

1 finding from 1 review

Vitamin A vs placebo

Adverse events: yellowing of the skin · healthy people and healthy male physicians

Vitamin A leads to higher adverse events: yellowing of the skin compared with placebo (high certainty).

1 finding from 1 review

Vitamin A vs placebo

Adverse events: minor gastrointestinal symptoms · healthy people and healthy male physicians

Vitamin A leads to higher adverse events: minor gastrointestinal symptoms compared with placebo (high certainty).

1 finding from 1 review

Vitamin A vs placebo

Incidence: all cancers · healthy people and healthy male physicians

Vitamin A showed no clear difference in incidence: all cancers compared with placebo (high certainty).

1 finding from 1 review

Vitamin A vs placebo

Mortality: all cancers · healthy people and healthy male physicians

Vitamin A showed no clear difference in mortality: all cancers compared with placebo (high certainty).

1 finding from 1 review

Vitamin A vs placebo

Mortality: all causes ‐ smokers and asbestos workers · healthy people and healthy male physicians

Vitamin A leads to higher mortality: all causes ‐ smokers and asbestos workers compared with placebo (high certainty).

1 finding from 1 review