Findings

What do systematic reviews say?

Refine by population, intervention, comparison or outcome
More filters
Evidence found and GRADE certainty

948 questions · 998 findings · 100 reviews · Headline outcomes only

No studies found 233 · 23.3%GRADE not reported 40 · 4%Very low 203 · 20.3%Low 271 · 27.2%Moderate 176 · 17.6%High 75 · 7.5%

Summary of findings table ‐ Vitamin B12 supplementation vs no supplementation or placebo

Preterm birth · pregnant women

Summary of findings table ‐ Vitamin B12 supplementation showed no clear difference in preterm birth (< 37 weeks) compared with placebo/no vitamin B12 supplementation (low certainty).

1 finding from 1 review

High‐treatment‐dose vitamin D (greater than 1000 IU/day) vs low‐treatment‐dose vitamin D (400 IU/day to 1000 IU/day)

Clinical relapse · people with inflammatory bowel disease

High‐treatment‐dose vitamin D (greater than 1000 IU/day) showed no clear difference in clinical relapse at end of study (52 weeks) compared with low‐treatment‐dose vitamin D (400 IU/day to 1000 IU/day) (low certainty).

1 finding from 1 review

High‐treatment‐dose vitamin D (greater than 1000 IU/day) vs low‐treatment‐dose vitamin D (400 IU/day to 1000 IU/day)

Withdrawals due to adverse events · people with inflammatory bowel disease

It is very uncertain whether high‐treatment‐dose vitamin D (greater than 1000 IU/day) changes withdrawals due to adverse events compared with low‐treatment‐dose vitamin D (400 IU/day to 1000 IU/day) (very low certainty).

1 finding from 1 review