This page shows what was measured, who it was measured in, and what that does not settle.
What Retinol does in the body
Vitamin A prevents retardation of growth and preserves the epithelial cells' integrity.
From the FDA-approved label: Beta-carotene, retinol, and retinal have effective and reliable vitamin A activity. Retinal and retinol are in chemical equilibrium in the body and have equivalent antixerophthalmic activity. Retinal combines with the rod pigment, opsin, in the retina to form rhodopsin, necessary for visual dark adaptation. Normal adult liver storage is sufficient to satisfy two years' requirements of vitamin A. Vitamin A is readily absorbed from the gastrointestinal tract, where the biosynthesis of vitamin A from beta-carotene takes place. Vitamin A absorption requires bile salts, pancreatic lipase, and dietary fat.
Why people take it. Temporary protects and relieves Minor cuts Scrapes Burns Chapped or cracked skin and lips
What happened in people
RNAWiki has not yet published a reviewed conclusion for this use.
§ A fixed RNAWiki sentence
Where this came from
Wording RNAWiki always uses, not a finding about this substance.
No reviewed claim names a result for any goal on this record.
No source is stored against this line.
The limit that matters most
Not recorded.
Where it acts
Not recorded.
Kind of result
No result is published, so no kind of result applies yet
Supervision
Not usually supervised: sold as a supplement or food ingredient where recorded. That is a legal category, not a safety judgement.
What the registries record it as
The substance registry classes this as mixture.
FDA substance registry · 81G40H8B0T · read 2026-08-29
The supplement label database classes it as vitamin, under the name Vitamin A.
A person wrote this explanation into the record, with the studies named in the path below.
The use the label states, quoted from it. It is written for a clinician, not for a reader without medical training.
No statement of the main limit is recorded.
The four opening statements run to 129 words.
Words this page uses
Four words worth knowing first
Chosen from what this page shows, with each one explained before the word it depends on.
Stand-in result
A stand-in result is a number measured because the real result takes too long.
A picture of it, and where the picture fails
It is like judging a journey by the speedometer rather than by arriving.
Where that stops being true. Speed does predict arrival. Many stand-in results do not predict the real one.
What people get wrong. A stand-in result is often reported as the result itself.
A surrogate endpoint substituted for a clinical endpoint, valid only where the substitution has been shown to hold.
Enzyme
An enzyme is a protein that speeds up one chemical change.
A picture of it, and where the picture fails
An enzyme is like a machine on a production line doing one cut.
Where that stops being true. A machine is switched on and off by a person. Enzymes are controlled by the cell.
What people get wrong. Enzymes are thought to be used up. They are not; they work again and again.
A catalytic protein that lowers the activation energy of a specific reaction.
Receptor
A receptor is a part of a cell that a signal fits into.
A picture of it, and where the picture fails
A receptor is like a lock waiting for one key.
Where that stops being true. A lock either opens or does not. A receptor can be half-triggered, or worn out.
What people get wrong. Fitting a receptor is read as causing a benefit. It causes a step, and nothing more.
A protein that binds a specific ligand and converts that binding into a cellular response.
Pathway
A pathway is a chain of steps inside a cell, each one setting off the next.
A picture of it, and where the picture fails
A pathway is like a row of dominoes.
Where that stops being true. Dominoes fall one way. Pathways loop back and can switch themselves off.
What people get wrong. Changing one step is read as changing the outcome. Other steps often absorb it.
An ordered series of molecular interactions producing a defined cellular change.
What happened in people◇Read from sources, not yet reviewed
What was measured, goal by goal
One row for each goal a registered study measured something for. One column for each kind of thing that could be measured.
Registered studies list 30 outcome measures that RNAWiki could read. A registered study says what someone planned to measure. It does not say what they found. 0 of the matched studies tested this substance, and 0 posted a result.
There is no single score. A strong test result and a weak life result are different facts.
Goals down the side, kinds of measurement across the top. Each cell says what kind of thing was registered, not what was found.
Goal
Life outcome
What a body can do
How a person feels
A test result
A step in the body
Harms
How long
Who was studied
Cholesterol
∅Nothing in the sources checkedNo registered study lists a life outcome for this goal.
∅Nothing in the sources checkedNo registered study lists a performance measure for this goal.
∅Nothing in the sources checkedNo registered study lists a symptom measure for this goal.
△Only a number moved3 registered test measure.
∅Nothing in the sources checkedNo registered study lists a body-step measure for this goal.
—Not recordedHarms were not a registered measure for this goal.
—Not recordedNo finished study window is recorded.
…Waiting for a reviewerWho was studied is listed further down the page.
Healthy ageing
…Waiting for a reviewer2 registered study measure of this kind. No reviewed result yet.
∅Nothing in the sources checkedNo registered study lists a performance measure for this goal.
∅Nothing in the sources checkedNo registered study lists a symptom measure for this goal.
∅Nothing in the sources checkedNo registered study lists a test result for this goal.
∅Nothing in the sources checkedNo registered study lists a body-step measure for this goal.
—Not recordedHarms were not a registered measure for this goal.
—Not recordedNo finished study window is recorded.
…Waiting for a reviewerWho was studied is listed further down the page.
Energy
∅Nothing in the sources checkedNo registered study lists a life outcome for this goal.
∅Nothing in the sources checkedNo registered study lists a performance measure for this goal.
…Waiting for a reviewer1 registered symptom measure.
∅Nothing in the sources checkedNo registered study lists a test result for this goal.
∅Nothing in the sources checkedNo registered study lists a body-step measure for this goal.
—Not recordedHarms were not a registered measure for this goal.
—Not recordedNo finished study window is recorded.
…Waiting for a reviewerWho was studied is listed further down the page.
Mood
∅Nothing in the sources checkedNo registered study lists a life outcome for this goal.
∅Nothing in the sources checkedNo registered study lists a performance measure for this goal.
∅Nothing in the sources checkedNo registered study lists a symptom measure for this goal.
∅Nothing in the sources checkedNo registered study lists a test result for this goal.
∅Nothing in the sources checkedNo registered study lists a body-step measure for this goal.
—Not recordedHarms were not a registered measure for this goal.
—Not recordedNo finished study window is recorded.
…Waiting for a reviewerWho was studied is listed further down the page.
Which registered measures put each goal on this table
Cholesterol
serum total cholesterol; serum hdl cholesterol; serum triglycerides level
Healthy ageing
mortality; 28 days mortality
Energy
fatigue scores
Mood
depression
Sorted by fixed word lists, version v1. A name the rules do not recognise stays unsorted rather than moving to the nearest column.
What each mark on this table means
∅ Nothing in the sources checked
No registered study lists a life outcome for this goal.
△ Only a number moved
3 registered test measure.
— Not recorded
Harms were not a registered measure for this goal.
… Waiting for a reviewer
Who was studied is listed further down the page.
What happened in people◇Read from sources, not yet reviewed
What happened in people
Each card is one study: the exact question it asked, who was in it, and whether it showed what it set out to show.
childhood mortality rate at age 1-6
✗ The study did not show it
Who was studied
NCT00222547
How many people
720000
Study design
Phase 4
Compared against
Not recorded for this study
Kind of result
Living longer, or avoiding a major event
What was found
Result not recorded on this page
Repeated elsewhere
Unreplicated
What this does not prove. A study that did not show an effect does not show that no effect exists anywhere.
The limits of this study, and where it came from
Main limit. No limitation is recorded for this study.
How far it carries. This study is recorded from the curated record, not from the registry match.
Form and route. Oral
Interval reported. Not recorded in this summary
Written into the record, not signed off as a reviewed claim.
openFDA NDC Directory · a recorded source, not a stored snapshot
openFDA SPL label · a recorded source, not a stored snapshot
NIH Dietary Supplement Label Database · a recorded source, not a stored snapshot
PubChem PUG-REST · a recorded source, not a stored snapshot
All-cause mortality
✗ The study did not show it
Who was studied
NCT04716712
How many people
694400
Study design
Phase 4
Compared against
Not recorded for this study
Kind of result
Living longer, or avoiding a major event
What was found
Result not recorded on this page
Repeated elsewhere
Unreplicated
What this does not prove. A study that did not show an effect does not show that no effect exists anywhere.
The limits of this study, and where it came from
Main limit. No limitation is recorded for this study.
How far it carries. This study is recorded from the curated record, not from the registry match.
Form and route. Oral
Interval reported. Not recorded in this summary
Written into the record, not signed off as a reviewed claim.
openFDA NDC Directory · a recorded source, not a stored snapshot
openFDA SPL label · a recorded source, not a stored snapshot
NIH Dietary Supplement Label Database · a recorded source, not a stored snapshot
PubChem PUG-REST · a recorded source, not a stored snapshot
Pregnancy-related mortality and all cause mortality
✗ The study did not show it
Who was studied
NCT00211341
How many people
100000
Study design
Phase 3
Compared against
Not recorded for this study
Kind of result
Living longer, or avoiding a major event
What was found
Result not recorded on this page
Repeated elsewhere
Unreplicated
What this does not prove. A study that did not show an effect does not show that no effect exists anywhere.
The limits of this study, and where it came from
Main limit. No limitation is recorded for this study.
How far it carries. This study is recorded from the curated record, not from the registry match.
Form and route. Oral
Interval reported. Not recorded in this summary
Written into the record, not signed off as a reviewed claim.
openFDA NDC Directory · a recorded source, not a stored snapshot
openFDA SPL label · a recorded source, not a stored snapshot
NIH Dietary Supplement Label Database · a recorded source, not a stored snapshot
PubChem PUG-REST · a recorded source, not a stored snapshot
Fragility fracture
✗ The study did not show it
Who was studied
NCT02536898
How many people
94260
Study design
Not applicable
Compared against
Not recorded for this study
Kind of result
A number that stands in for health
What was found
Result not recorded on this page
Repeated elsewhere
Unreplicated
What this does not prove. A study that did not show an effect does not show that no effect exists anywhere.
The limits of this study, and where it came from
Main limit. No limitation is recorded for this study.
How far it carries. This study is recorded from the curated record, not from the registry match.
Form and route. Oral
Interval reported. Not recorded in this summary
Written into the record, not signed off as a reviewed claim.
openFDA NDC Directory · a recorded source, not a stored snapshot
openFDA SPL label · a recorded source, not a stored snapshot
NIH Dietary Supplement Label Database · a recorded source, not a stored snapshot
PubChem PUG-REST · a recorded source, not a stored snapshot
Incidence rate of Thromboembolic events
✗ The study did not show it
Who was studied
NCT03367325
How many people
63001
Study design
Not applicable
Compared against
Not recorded for this study
Kind of result
A number that stands in for health
What was found
Result not recorded on this page
Repeated elsewhere
Unreplicated
What this does not prove. A study that did not show an effect does not show that no effect exists anywhere.
The limits of this study, and where it came from
Main limit. No limitation is recorded for this study.
How far it carries. This study is recorded from the curated record, not from the registry match.
Form and route. Oral
Interval reported. Not recorded in this summary
Written into the record, not signed off as a reviewed claim.
openFDA NDC Directory · a recorded source, not a stored snapshot
openFDA SPL label · a recorded source, not a stored snapshot
NIH Dietary Supplement Label Database · a recorded source, not a stored snapshot
PubChem PUG-REST · a recorded source, not a stored snapshot
All-cause, Pregnancy-related Mortality
✗ The study did not show it
Who was studied
NCT00198822
How many people
59666
Study design
Phase 3
Compared against
Not recorded for this study
Kind of result
Living longer, or avoiding a major event
What was found
Result not recorded on this page
Repeated elsewhere
Unreplicated
What this does not prove. A study that did not show an effect does not show that no effect exists anywhere.
The limits of this study, and where it came from
Main limit. No limitation is recorded for this study.
How far it carries. This study is recorded from the curated record, not from the registry match.
Form and route. Oral
Interval reported. Not recorded in this summary
Written into the record, not signed off as a reviewed claim.
openFDA NDC Directory · a recorded source, not a stored snapshot
openFDA SPL label · a recorded source, not a stored snapshot
NIH Dietary Supplement Label Database · a recorded source, not a stored snapshot
PubChem PUG-REST · a recorded source, not a stored snapshot
What we know
RNAWiki holds 6 written-up human studies for this substance, each with the question it asked.
How we know it
Each card names the study, the number of people and what the study set out to measure.
What this does not prove
These summaries were written by a person and have not been signed off as reviewed claims.
Why it matters
A study that failed is as informative as one that worked, and both are here.
What we still do not know
No reviewed claim exists, so no exact population, effect size or interval is published yet.
What happened in people◇Read from sources, not yet reviewed
How close this is to real life
The top step is something a person would feel or care about. The bottom is a guess from software. Filled steps are where evidence exists for this substance.
■Living longer, or avoiding a major eventEvidence recorded. Death, a heart attack, a stroke, a hospital stay.5 registered measures of this kind. No reviewed result.
■What a body can do day to dayEvidence recorded. Walking, dressing, breathing, recovering.1 registered measure of this kind.
■Measured performanceEvidence recorded. How much was lifted, how far was run, how fast.1 registered measure of this kind.
■Symptoms and quality of lifeEvidence recorded. Pain, tiredness, mood, sleep, as the person rated it.1 registered measure of this kind.
■A number that stands in for healthEvidence recorded. Cholesterol, blood sugar, bone density. A stand-in, not the thing itself.3 registered measures of this kind.
■A step measured inside a personEvidence recorded. Something measured in human tissue or human cells.A human record sits on the stored organism ladder.
■AnimalsEvidence recorded. Mice, rats, dogs. Useful for ideas, not proof about people.Stored records in C. elegans (roundworm), Mouse. A result in animals says what to test next. It does not say what happens in people.
■Cells in a dishEvidence recorded. Cells or chemistry on a bench, far from a whole body.Stored mechanism abstracts describe steps measured in cells or tissue.
□A guess from softwareNo evidence recorded. Nobody measured it. RNAWiki never publishes one as a finding.RNAWiki stores no prediction for this record. Software can suggest a link. RNAWiki does not publish one as a finding.
Higher on these steps means closer to something a person would feel. It does not mean better done.
What it would be like to take◇Read from sources, not yet reviewed
Felt, measured, or meaningful
Three different things that get called the same word. Registered studies measured all three, and mixing them is how a blood test becomes a health claim.
Felt
Things a person could notice without a test.
fatigue scores
Measured
Things only a test, a scale or a device shows.
serum total cholesterol
serum hdl cholesterol
serum triglycerides level
Meaningful
Things that change how a life goes, not only a number.
mortality
expanded disability status scale
28 days mortality
overall survival
progression free survival
duration of hospitalization
A registered study says what someone planned to measure. It does not say what they found. A number moving is not the same as a life going better. The two are shown apart here.
Felt, but not shown to help. A person notices a change. No study showed it leads anywhere good.
Measured, but not felt. A number moves. The person notices nothing. Both can be true.
Measured, but not shown to matter. A number moves in the good direction. Nobody showed that lives went better.
Matters, but takes years. The result that counts may take longer than anyone would keep watching.
These are harms, study-process measures, or names the rules did not recognise. They are shown rather than dropped.
What is missing or unclear◇Read from sources, not yet reviewed
Were people like you studied?
RNAWiki cannot tell whether a study fits you. It can show who was in it, and where the result stops carrying.
Who was studied
People similar to this profile were included.
Retinyl palmitate injection is effective for the treatment of vitamin A deficiency. The parenteral administration is indicated when the oral administration is not feasible as in anorexia, nausea, vomiting, pre- and postoperative conditions, or it is not available as in the “Malabsorption Syndrome” with accompanying steatorrhea.
Who is missing from the studies
Which groups were under-represented in the studies has not been recorded for this substance. Pregnancy, breastfeeding, children, older adults, and people with liver or kidney conditions are commonly excluded from trials; nothing here says whether they were.
Where the result stopped carrying
This is a scope explorer, not a diagnosis engine.
It shows who was studied so you can see whether people similar to you were included.
RNAWiki cannot tell whether a study fits you. It can show who was in it.
What it would be like to take◇Read from sources, not yet reviewed
Why it might seem to do nothing
A real effect and a noticed effect are different things. These are the recorded reasons the two come apart.
It was studied for a different goal
The studies measured something else entirely.
On this record: Some registered studies measured things that match no goal on this page.
It was studied in different people
The people in the studies were not much like the reader.
On this record: Which groups were under-represented in the studies has not been recorded for this substance. Pregnancy, breastfeeding, children, older adults, and people with liver or kidney conditions are commonly excluded from trials; nothing here says whether they were.
The evidence may simply be wrong
Small early studies often do not hold up.
On this record: RNAWiki has not yet published a reviewed conclusion for this use.
Other reasons RNAWiki checked and found nothing for (10)
A different form was studied
The studied form is not the form on the shelf. Nothing in this record points to this reason.
There was nothing to correct
Where a level is already normal, topping it up may change nothing. Nothing in this record points to this reason.
Something else had to happen too
In the studies it was paired with training, a diet or another treatment. Nothing in this record points to this reason.
The change is too small to feel
A real change can still sit below what a person notices. Nothing in this record points to this reason.
Day-to-day swing hides it
Sleep, food, stress and time of day move most numbers more than this would. Nothing in this record points to this reason.
Not enough time yet
The studies ran longer than the person has waited. Nothing in this record points to this reason.
It was not taken as studied
Missed days change the result, and studies count them. Nothing in this record points to this reason.
Something else changed at the same time
Two changes at once cannot be told apart afterwards. Nothing in this record points to this reason.
The product may not be what it says
Contents of a sold product are not always what the label states. Nothing in this record points to this reason.
No recorded reason
RNAWiki has nothing stored that would explain it. Nothing in this record points to this reason.
None of these is a reason to take more. Taking more is not a step this page ever suggests.
What it would be like to take◇Read from sources, not yet reviewed
What taking it involves
The recorded facts about getting hold of it and using it. Nothing here is a suggestion about what you should do.
How it is supplied
Prescription only
❝ Quoted from a source
Where this came from
Copied from a source RNAWiki stored, with the source named.
Read from the recorded approval status.
No source is stored against this line.
Form and route
Oral
✎ Source-linked record
Where this came from
A person wrote this into the record with the study named beside it. No reviewer has signed it off.
The form and route recorded on this substance.
No source is stored against this line.
Who oversees it
Not usually supervised: sold as a supplement or food ingredient where recorded. That is a legal category, not a safety judgement.
❝ Quoted from a source
Where this came from
Copied from a source RNAWiki stored, with the source named.
The identity record classes it as a supplement ingredient; no medicines register records an approval.
No source is stored against this line.
What is in the pack
Sold as capsule, injectable, for solution, solution, given by the oral, intravenous, injection route.
✎ Source-linked record
Where this came from
A person wrote this into the record with the study named beside it. No reviewer has signed it off.
Recorded notes on how this is sold and what that means for what is in the pack.
No source is stored against this line.
Where it is registered
Regulatory records are listed in the technical disclosure at the foot of this page.
# Counted from records
Where this came from
A count of rows RNAWiki holds. It describes our records, not your body.
Register entries are stored per jurisdiction and shown with their dates.
No source is stored against this line.
Why people stop
Not recorded.
∅ Nothing recorded
Where this came from
RNAWiki holds nothing here and says so rather than guessing.
No record of why people stopped taking it is stored for this substance.
No source is stored against this line.
What it would be like to take∅Nothing found in the sources checked
What can go wrong
Sorted by where each line came from. A regulator's label and a report somebody sent in are not the same kind of fact.
∅Nothing found in the sources checked
No harm is recorded against this substance in the sources RNAWiki checked. Finding nothing is not the same as showing there is nothing.
The sources listed were searched and held nothing. That is not the same as nothing existing.
Reports sent to a regulator
These are reports people sent to a regulator. They do not show the medicine caused the reaction.
Nobody counted how many people took the medicine and reported nothing.
The same event can be reported more than once, and many reports are incomplete.
News coverage, lawsuits and new warnings change how often people report.
A count is not a rate and not a risk.
Retinol appears in spontaneous reports to regulators. Across the 10 most-reported reaction terms, 363 reaction mentions were counted. One report can name several reactions.
open-targets-adr · recorded 2026-06-24 · a recorded source, not a stored snapshot
Over a long time. No completed tested study window is recorded, so long-term effects are not established by the registry record.
Groups the studies covered thinly. Which groups were under-represented in the studies has not been recorded for this substance. Pregnancy, breastfeeding, children, older adults, and people with liver or kidney conditions are commonly excluded from trials; nothing here says whether they were.
What is missing or unclear◇Read from sources, not yet reviewed
Does the exact form matter?
Evidence belongs to the exact thing that was tested. A different salt, a different mixture or a different preparation is a different question.
The form that was studied
Oral
✎ Source-linked record
Where this came from
A person wrote this into the record with the study named beside it. No reviewer has signed it off.
The form used in the studies cited on this page.
No source is stored against this line.
What is sold
Not recorded.
∅ Nothing recorded
Where this came from
RNAWiki holds nothing here and says so rather than guessing.
Nothing further is recorded about which forms are sold.
No source is stored against this line.
What is recorded as being sold
87 products list this as an active ingredient in the United States drug directory. None of them contains it on its own, so nothing on this page can separate it from what it is combined with.
FDA National Drug Code directory · 83027-0053 · read 2026-08-29
They are sold as capsule, gelatin coated, cream, liquid, powder, solution and solution/ drops, taken extracorporeal, oral and sublingual.
FDA National Drug Code directory · 83027-0053 · read 2026-08-29
80 published labels name it as an active ingredient. None of them describes this substance alone, so no label text on this page can be attributed to it rather than to a combination.
US prescribing information · b8e08798-d8bb-4616-996b-a2c07a5d730a · read 2026-08-29
Those labels are classed as human otc drug and human prescription drug.
US prescribing information · b8e08798-d8bb-4616-996b-a2c07a5d730a · read 2026-08-29
Flotrex is oral at HOW SUPPLIED Flotrex™ Multivitamin Chewable plus 0.25 mg Fluoride Tablets are purple-colored, grape-flavored, unscored tablets available by prescription only in bottles of 30 tablets., recorded as fda label in effect 2025-07-14 in the United States.
US prescribing information · 30186998-2121-3ef2-e063-6394a90a513e · read 2026-08-30
Evidence carries across two names for one substance. It does not carry across a salt, a mirror form or a mixture.
What it would be like to take◇Read from sources, not yet reviewed
What you could measure
This one is decided with a clinician, so this section holds questions to ask rather than a plan to run.
A single-person plan is offered only as a structure for observing yourself. It never calculates an amount to take, and it cannot prove cause.
Questions worth asking
Which of the trials of Retinol studied people like me?
What was measured, and for how long?
Was the result a laboratory value or a health outcome?
What would we watch for, and when would we stop?
Tracking can show whether something changed for you. It cannot show what caused it.
RNAWiki records evidence. It does not say whether this substance is right for you.
What is missing or unclear◇Read from sources, not yet reviewed
What nobody knows yet
Open questions, each with why it is open and what would close it.
How fast does the body clear it?
The sources RNAWiki checked hold nothing for this field.
Why it matters. Without this, nothing on this page can say how long anything lasts.
What would answer it
A stored source that records it, and a reviewer to sign it off.
Last checked 2026-09-04. Searched: The sources listed in the receipts at the foot of this page.
Missing populations
Which groups were under-represented in the studies has not been recorded.
Why it matters. Recorded by the evidence model as a gap on this record.
What would answer it
A study that measures it, and a reviewer to sign it off.
Last checked 2026-09-04. Searched: The sources listed in the receipts at the foot of this page.
Missing long-term data
No completed tested study window is recorded.
Why it matters. Recorded by the evidence model as a gap on this record.
What would answer it
A study that measures it, and a reviewer to sign it off.
Last checked 2026-09-04. Searched: The sources listed in the receipts at the foot of this page.
No reviewed conclusion
RNAWiki has not yet published a reviewed conclusion for this use.
Why it matters. Recorded by the evidence model as a gap on this record.
What would answer it
A study that measures it, and a reviewer to sign it off.
Last checked 2026-09-04. Searched: The sources listed in the receipts at the foot of this page.
Missing interaction studies
No interaction was found in the registers checked. Not finding one is not the same as showing there is none.
Why it matters. Recorded by the evidence model as a gap on this record.
What would answer it
A study that measures it, and a reviewer to sign it off.
Last checked 2026-09-04. Searched: The sources listed in the receipts at the foot of this page.
Formulation uncertainty
Several salts, forms or products of Retinol are recorded. Results from one form may not transfer to another.
Why it matters. Recorded by the evidence model as a gap on this record.
What would answer it
A study that measures it, and a reviewer to sign it off.
Last checked 2026-09-04. Searched: The sources listed in the receipts at the foot of this page.
Mechanism not reviewed
No reviewed mechanism story exists for this substance.
Why it matters. Recorded by the evidence model as a gap on this record.
What would answer it
A study that measures it, and a reviewer to sign it off.
Last checked 2026-09-04. Searched: The sources listed in the receipts at the foot of this page.
What happened in people◇Read from sources, not yet reviewed
Check any of this yourself
Every line above traced back to the study it came from. This is the technical layer, and the vocabulary changes here.
Where else this substance is registered
FDA substance identifier (UNII)
81G40H8B0T
CAS registry number
11103-57-4
ChEMBL
CHEMBL986
ChEBI
17336
RxNorm concept
11246
European Chemicals Agency number
234-328-2
DrugBank
DB00162
Checks this page had to pass
✓ Passed
Identity resolved
no open identity hold
✓ Passed
No unresolved merge across substance families
no quarantine open
✓ Passed
Every public sentence names a source
The opening statement carries the origin: Written into the record, not signed off.
✗ Not passed
Trial roles classified for highlighted evidence
No registered study is classified as testing this substance.
✓ Passed
No internal keys in reader text
enforced by the copy-contract test over the rendered page
✓ Passed
Safety mode resolved
The identity record classes it as a supplement ingredient; no medicines register records an approval.
✓ Passed
Canonical metadata present
slug and display name present
What is missing or unclear◇Read from sources, not yet reviewed
How this medicine reached us
Kept near the foot of the page. A historical event moves up only when it changes something about this substance today.
What the approval register records
16 approved applications cover products containing this substance. The earliest was NDA008809, approved 19530220 to HOSPIRA.
This order is fixed in code and does not count clicks or time on the page.
What is not here
6 questions this page could not answer
These sections were prepared and left out because there was nothing to put in them. They are listed rather than hidden, so the gaps in this record are visible.
The path through the body — found nothing in the sources checked.
How long anything takes — found nothing in the sources checked.
What it may clash with — found nothing in the sources checked.
Other ways to the same goal — found nothing in the sources checked.
Claims that go past the evidence — found nothing in the sources checked.
What changed on this page — found nothing in the sources checked.
The record as stored
The full record, for auditing
Everything above is built from what is below. This layer keeps the technical vocabulary, record identifiers and every stored row, so a reader who wants to check the page can.
Recorded evidence blocks (13)
Q1
What did Retinol's largest trial (720000 people) and its longest (23 years) measure?
720000 people in Retinol's largest registered study, 23 years in its longest registered window, measuring mortality in first 6 months of life. ClinicalTrials.gov · 2026-09-01
27 na, 16 phase4, 14 phase2, 13 phase3, 5 early phase1, 4 phase1; NCT00198718; 2020-12-31. Last human test completed 2024, NCT06105476.
Interpretation These counts include studies where Retinol was a comparison treatment, a background treatment or an exposure in an observational study, and the longest window may be a planned end date. Trial roles have not yet been classified for this record.
Show the evidence
na
27
phase4
16
phase2
14
phase3
13
early phase1
5
phase1
4
1 more recorded row
Last recorded human testNCT06105476
2024-03-31
recorded 2026-09-01 · last checked 2026-09-04
Q2
From C. elegans to human: where has Retinol shown lifespan?
2 recorded entries; human; oral; also "Vitamin A 100,000 IU"
Show the evidence
human
NCT00114868
oral; vitamin A (retinol palmitate) oral, 48,000 IU
NCT03152474
Vitamin A 100,000 IU
recorded 2026-09-01 · last checked 2026-09-04
Q5
Did Retinol move GrimAge, and by how much?
GrimAge: "Summary-level data about 4 dietary antioxidants (vitamin A, vitamin C, vitamin E and carotene) and 4 epigenetic age measures (HannumAge, Intrinsic epigenetic age acceleration [IEAA], GrimAge and PhenoAge) were respectively got from FinnGen Project Database and a meta-analysis of 28 genome-wide association studies…" Europe PMC · epigenetic clock search · 2025-10-01
5 recorded sentences; 2025, 2024; biomarker
Show the evidence
GrimAgePMID 41261720
2025; "Summary-level data about 4 dietary antioxidants (vitamin A, vitamin C, vitamin E and carotene) and 4 epigenetic age measures (HannumAge, Intrinsic epigenetic age acceleration [IEAA], GrimAge and PhenoAge) were respectively got from FinnGen Project Database and a meta-analysis of 28 genome-wide association studies (GWAS) involving 34,710 European participants."
epigenetic agePMID 41261720
2025; "MR analyses found no significant effects of vitamin A, vitamin E and carotene on 4 epigenetic age measures."
PhenoAgePMID 40791230
2025; "Compared to the first quintile of vitamin A, the odds ratios (ORs) for PhenoAge acceleration in the next four quintiles were 1.24 (0.93-1.65), 1.04 (0.78-1.37), 0.95 (0.71-1.27), and 1.51 (1.13-2.01), respectively."
GrimAgePMID 40791230
2025; "In addition, a non-linear association was observed between serum levels of vitamin A with GrimAge acceleration, with an inflection point at 71.8 μg/dL."
epigenetic agePMID 39067141
2024; "In contrast, increased intakes of added sugar, gondoic acid, behenic acid, arachidonic acid, vitamin A and ash were associated with accelerated epigenetic ageing in postmenopausal women."
recorded 2025-10-01 · last checked 2026-09-04
Q6
More Retinol was worse in human: at what point?
U-shaped in human: "As the concentration of vitamin A increases, the β coefficient exhibits a trend that initially decreases before subsequently increasing.The serum levels of both vitamin A and homocysteine across various genders and age groups demonstrate a U-shaped relationship." Europe PMC · dose-response search · 2026-01-23
6 recorded sentences naming Retinol; U-shaped, dose-response
Show the evidence
U-shaped
PMID 41578366
"As the concentration of vitamin A increases, the β coefficient exhibits a trend that initially decreases before subsequently increasing.The serum levels of both vitamin A and homocysteine across various genders and age groups demonstrate a U-shaped relationship."
PMID 41578366
"This U-shaped nonlinear association between vitamin A and homocysteine was also identified within the high-homocysteine group."
PMID 41578366
"CONCLUSION: This study found a U-shaped relationship between serum vitamin A and homocysteine levels in middle-aged and elderly Chinese people."
dose-response
PMID 41578366
"However, the dose-response relationship between homocysteine and vitamin A remains unclear among the middle-aged and elderly population in rural China."
PMID 41578366
"OBJECTIVE: This study investigates the dose-response relationship and threshold effect between serum homocysteine and vitamin A levels in vivo."
PMID 41578366
"METHODS: To examine the dose-response relationship between vitamin A and homocysteine, we used multiple linear regression, multinomial logistic regression, generalized additive models, and restricted cubic splines."
recorded 2026-01-23 · last checked 2026-09-04
Q7
Could one person measure Retinol's effect on humphrey field analyzer total 30 2 program?
Humphrey field analyzer total 30 2 program: measured in Retinol's trials.
humphrey field analyzer total 30 2 program is the recorded endpoint.
Show the evidence
biomarkers
humphrey field analyzer total 30 2 program; 2026-09-01
m at 1 5 months; 2026-09-01
mortality; 2026-09-01
morbidity; 2026-09-01
growth; 2026-09-01
endotoxin levels; 2026-09-01
14 more recorded rows
biomarkers
incidence of placental malaria; 2026-09-01
biomarkers
low birth weight; 2026-09-01
biomarkers
global photodamage severity; 2026-09-01
biomarkers
serum total cholesterol; 2026-09-01
biomarkers
serum hdl cholesterol; 2026-09-01
biomarkers
serum triglycerides level; 2026-09-01
biomarkers
complete blood count; 2026-09-01
biomarkers
expanded disability status scale; 2026-09-01
biomarkers
fatigue scores; 2026-09-01
biomarkers
depression; 2026-09-01
biomarkers
incidence of clinical malaria attacks; 2026-09-01
biomarkers
incidence of diarrhea; 2026-09-01
biomarkers
frequency of correct predictions; 2026-09-01
biomarkers
wrinkle appearance; 2026-09-01
human trials at or under30
13
Not recorded for this substance
a recorded half-life
smallest human trial
0; NCT00558480; NA; the smallest recorded human enrolment at or below 30; the registry states no direction of its result; WITHDRAWN
Q8
Which of 28 days mortality, at least one treatment emergent adverse event and change in appearance of skin pigmentation did Retinol's trials measure?
28 days mortality, at least one treatment emergent adverse event and change in appearance of skin pigmentation lead 30 outcome terms across Retinol's trials. ClinicalTrials.gov · 2026-09-01
Interpretation morbidity, growth, endotoxin levels, incidence of placental malaria, low birth weight and global photodamage severity follow.
Show the evidence
humphrey field analyzer total 30 2 program
1
m at 1 5 months
1
mortality
1
morbidity
1
growth
1
endotoxin levels
1
14 more recorded rows
incidence of placental malaria
1
low birth weight
1
global photodamage severity
1
serum total cholesterol
1
serum hdl cholesterol
1
serum triglycerides level
1
complete blood count
1
expanded disability status scale
1
fatigue scores
1
depression
1
incidence of clinical malaria attacks
1
incidence of diarrhea
1
frequency of correct predictions
1
wrinkle appearance
1
recorded 2026-09-01 · last checked 2026-09-04
Q9
Which of Retinol's 6 ongoing trials reports first?
Vitamin A dose that achieves level in the upper quartile of normal range for sex in at least 2/3 cases without dose limiting toxicity; Change of Blood Vitamin A and Nicotinamide Levels; latest 2029-08
Show the evidence
Trial
NCT03719092
"High Dose Vitamin A in Preventing Gastrointestinal GVHD in Participants Undergoing Donor Stem Cell Transplant"; n 62; "Vitamin A dose that achieves level in the upper quartile of normal range for sex in at least 2/3 cases without dose limiting toxicity"; 2026-12-31
NCT05702398
"Pilot Trial of Supplemental Vitamin A and Nicotinamide"; n 30; "Change of Blood Vitamin A and Nicotinamide Levels"; 2028-03-01
NCT05720559
"Early Blocking Strategy for Metachronous Liver Metastasis of Colorectal Cancer Based on Pre-hepatic CTC Detection"; n 100; "Metachronous liver metastasis rate"; 2026-09-01
NCT06450925
"Vitamin A Supplementation in Allogeneic Stem Cell Transplantation."; n 190; "Incidence of moderate-severe chronic graft versus host disease (GVHD)"; 2029-08
NCT06508099
"Vitamin A and D Supplementation in Allogeneic HCT"; n 220; "Cumulative incidence of gastrointestinal acute GVHD"; 2027-05
NCT07335991
"Effect of Vitamin A Supplementation on Idiopathic Scoliosis"; n 140; "Scoliosis Curve Angle"; 2028-06-01
recorded 2026-09-01 · last checked 2026-09-04
Q10
Which 36 trials of Retinol posted no result?
Posted no result
36 of 36 completed trials
Registrations
NCT00000114, NCT01203488, NCT03152474, NCT00114868, NCT00000116 and NCT00168584, and 30 more
Completion dates
oldest 1987-06; newest 2024-03-31
Show the evidence
Trial
NCT00000114
1987-06
NCT01203488
1999-07
NCT03152474
2000-01
NCT00114868
2001-04
NCT00000116
2002-09
NCT00168584
2003-08
14 further recorded trials
NCT00222547
2005-02
NCT00170404
2005-10
NCT00133419
2006-01
NCT00053612
2006-06
NCT00388921
2007-12-31
NCT00211341
2008-10
NCT00742937
2008-12
NCT01634698
2008-12
NCT00065455
2009-05-06
NCT01782001
2009-11
NCT00417404
2009-12
NCT00817661
2010-07
NCT00674089
2010-10
NCT00707785
2012-06
Q11
At the median, Retinol's trials enrolled 169 people — anything larger?
Median enrolment
169
Largest enrolment
720000
Registered trials counted
74
Q12
What do 363 spontaneous reports say about Retinol — and not say?
These are reports people sent to a regulator. They do not show the medicine caused the reaction. Nobody counted how many people took the medicine and reported nothing. The same event can be reported more than once, and many reports are incomplete. News coverage, lawsuits and new warnings change how often people report. A count is not a rate and not a risk.
Retinol appears in spontaneous reports to regulators. Across the 10 most-reported reaction terms, 363 reaction mentions were counted: coma 71; somnolence 71; gastrooesophageal reflux disease 70; pneumonia aspiration 70. open-targets-adr · CHEMBL986 · 2026-06-24
Show the evidence
coma
71
somnolence
71
gastrooesophageal reflux disease
70
pneumonia aspiration
70
hypercalcaemia
25
hypervitaminosis a
17
4 more recorded rows
flushing
11
hepatotoxicity
10
drug-induced liver injury
9
premature baby
9
recorded 2026-06-24 · last checked 2026-09-04
Q13
What is recorded about Retinol and autophagy?
"Host factors, such as retinol-binding protein 4 (RBP4), act as restriction factors by counteracting viral strategies through autophagy modulation." — where Retinol and autophagy appear together. Europe PMC · pathway abstract search · 2025-09-09
autophagy; PMID 40995216
Show the evidence
autophagyPMID 40995216
"Host factors, such as retinol-binding protein 4 (RBP4), act as restriction factors by counteracting viral strategies through autophagy modulation."
recorded 2025-09-09 · last checked 2026-09-04
Where it is registeredIdentifiers, relations and other names
Arovit, Nepalm, Ro-a-vit, Vitamin a 1, Aoao Retinol Anti-Aging Box Set, Anti-Aging Eye Mask, Noavia Retinol Moisturizer, Instant Anti Aging Wrinkle Eye Treatment Syringe, Anti Age Skin, Aquasol A, Vi-Dom-A, Alphalin
Development code
NSC-122759
Also called
Vitamin a, retinoic acid, retinyl palmitate, vas, vitamin a palmitate, vitamin a supplementation, CHOCOLA A, HYDROVIT A, LUTAVIT A, MICROVIT A, PROVITAMIN A, ROVIMIX A 500
Salt form
Vitamin A Acetate, Chanvida Broad Spectrum Bb Cream, Aoao Retinol Anti-Aging Box Set / Anti-Aging Eye Mask / Noavia Retinol Moisturizer / Instant Anti Aging Wrinkle Eye Treatment Syringe / Chanvida Broad Spectrum Bb Cream / Anti Age Skin
Sources (10)
Sources
ClinicalTrials.govclinicaltrials.gov ·
ClinicalTrials.govClinicalTrials.gov API v2 snapshot 2026-09-01T09:00:05 ·
ChEMBL ATC CC BY-SA · ClinicalTrials.gov — US Government work · Europe PMC — metadata only, under the recorded legal gate · Open Targets 26.06 — CC0 · derived from this page's own recorded fields; no external licence · mixed register set; per-register licences in docs/specs/corpus-20k-sources.md
✗ required summary fields resolved: 5 required field(s) not terminal: Why people use it, Best-supported result, Most important common problem, Biggest unanswered question, Human evidence
✓ public claims reviewed: 0 reviewed claim(s); drafts are never rendered
✓ source coverage passed: 10 source rows
✓ no critical contamination: no quarantine open
✓ canonical metadata passed: slug and display name present
✓ no raw internal fields: enforced by the copy-contract test over the rendered page
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