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Open WellbeingWhat the studies actually measured

Skin, hair and nails

Vitamin A Beta Caroteneand Skin Health

Only one source here so far, and it measured higher skin Health.

How sure anyone can be

Low certainty, level 2 of 4

Further research is likely to change this.

The numbers reported

0.5
standardized mean difference increase in photoprotective effect per additional month of supplementation (minimum 10 weeks)

None of these sources gave a likely range — the band the real answer probably sits in — so how precise these numbers are is still an open question here.

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 person went through the criteria and recorded which brought the rating down. Their reasons are not on record here.

  • Systematic review, 2008

    Low certainty, level 2 of 4

    Protection from sunburn with beta-Carotene--a meta-analysis.

    Köpcke W, Krutmann J. Protection from Sunburn with β-Carotene—A Meta-analysis. Photochem Photobiol. 2008;84(2):284-288. doi:10.1111/j.1751-1097.2007.00253.x. PMID:18086246.

    Number reported
    0.5
    Which way it went
    Higher
    Likely range
    Not in the abstract
    Source’s own words
    standardized mean difference increase in photoprotective effect per additional month of supplementation (minimum 10 weeks)
    Who was studied
    Adult
    Compared with
    placebo or control
    Amount taken
    Not in the abstract
    For how long
    Not in the abstract
    Disagreement between studies
    Not in the abstract
    Kind of record
    Meta-analysis
    How this rating was reachedstarts at High, 2 steps down: indirectness
    1. Starts at High
    2. Indirectness brought it down to ModerateThe reason for this step is not on record here.
    3. Indirectness brought it down to LowThe reason for this step is not on record here.
    4. Ends at Low2 steps down.
    Not written down for this rating
    risk of bias, imprecision and inconsistency

    Published before the signing gate; not yet re-verified.

    Read the abstract on PubMed

What is still missing from these readings

  • One gives no likely range, so how precise that number is is unknown.
  • One do not say how many people took part.
  • 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.

Vitamin A Beta Carotene is not on our to-read list

Vitamin A Beta Carotene is not on our to-read list, so nothing here is set out to read next for it.

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

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.