Long-term health and immunity
Zincand Common cold duration
Only one source here so far, and it measured lower common cold duration.
How sure anyone can be
Low certainty, level 2 of 4Further research is likely to change this.
The numbers reported
One source’s range, drawn against its own line of no difference and scaled to its own numbers.
-2.5-1.65-0.81
This range stays on one side of the no-difference line.
One source, newest first
What we read is the published abstract, not the full paper, so a blank below may still be printed in the paper itself. A fixed rule worked this out from the source’s own fields. Nobody checked this rating by hand.
Systematic review, 2012 · 17 studies pooled · 2,121 participants
Low certainty, level 2 of 4Zinc for the treatment of the common cold: a systematic review and meta-analysis of randomized controlled trials.
CMAJ. 2012;184(10):E551-61. doi:10.1503/cmaj.111990. PMID:22566526.
- Number reported
- -1.65
- Which way it went
- Lower
- Likely range
- -2.5 to -0.81
- Source’s own words
- days of cold symptoms, mean difference vs placebo
- Who was studied
- Adult and child
- Compared with
- placebo or no treatment
- Amount taken
- Not in the abstract
- For how long
- Not in the abstract
- Disagreement between studies
- I2 = 95%
- Kind of record
- Journal article
How this rating was reachedstarts at High, 2 steps down: imprecision and inconsistency
- Starts at High
- Imprecision brought it down to Moderatethe interval excludes no effect but spans a 3-fold range of effect size, from trivial to largeReported in the abstract
- Inconsistency brought it down to Lowheterogeneity across pooled studies is high (I² = 95%)Reported in the abstract
- Ends at Low2 steps down.
- Checked, nothing to step it down for
- risk of bias and indirectness
Imprecision stops at the first check that applies; others may apply too.
AI-reviewed & signed — an AI agent re-read this finding against the saved source and checked that the quote, the numbers, the units and the direction match it. No person read it. The owner authorised the agent to sign the batch with the owner's key, and every build rechecks that signature against these exact bytes.
What is still missing from these readings
- Amount taken — Not in the abstract.
- For how long — Not in the abstract.
Something nobody wrote down is never a zero and never a guess.
Still to read for Zinc
Three of the nine things on our list for Zinc have no reading here yet:
- Fetal heart-rate variability
- Serum copper
- Total testosterone
Still to read means nobody here has got to it, not that it was tried and did nothing or that no research exists. A pairing on no list is not a gap: we never set out to read it.
Read next
Zinc
Five other questions read for it
Long-term health and immunity
20 questions read under it
Common cold duration
No other ingredients read against it
Alphabetical, and by nothing else.
This is a library, not advice. No recommendation, no dose, no diagnosis, no ranking. We never ask about your symptoms, and nothing here is tailored to you.