Findings

What do systematic reviews say?

5 questions · 5 findings · 1 reviews

No studies found 1 · 20%GRADE not reported 0 · 0%Very low 0 · 0%Low 0 · 0%Moderate 1 · 20%High 3 · 60%

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

Drugs for preventing lung cancer in healthy people 2020 · Cochrane Headline outcomes only
RR 1.02 [0.88, 1.77]
1 study · 22071 participants
High

Mortality: all cancers · healthy male physicians, period: 1997 to 2007 and female health professionals, period: 1998 to 2005

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

1 finding from 1 review

Drugs for preventing lung cancer in healthy people 2020 · Cochrane Headline outcomes only
RR 1.11 [0.93, 1.34]
2 studies · 14953 participants
High

Mortality: all cancers · healthy people

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

1 finding from 1 review

Drugs for preventing lung cancer in healthy people 2020 · Cochrane Headline outcomes only
RR 1.11 [0.99, 1.24]
2 studies · 54517 participants
High

Mortality: all cancers · relatively healthy postmenopausal women

Vitamin D plus calcium showed no clear difference in mortality: all cancers compared with placebo (moderate certainty).

1 finding from 1 review

Drugs for preventing lung cancer in healthy people 2020 · Cochrane Headline outcomes only
RR 0.91 [0.78, 1.05]
1 study · 34670 participants
Moderate

Mortality: all cancers · healthy women, aged 35 to 60, and men, aged 45 to 60, living in France

The review found no eligible studies for this question.

1 finding from 1 review

Drugs for preventing lung cancer in healthy people 2020 · Cochrane Headline outcomes only
no estimate extracted
Studies not reported
No studies found