Vitamin A (Retinol)
Research reviewed: Up until 03/2026
Vitamin A (Retinol) (Retinol / Retinyl Palmitate / Retinoic Acid (Preformed Vitamin A)) is a dietary supplement with 5 published peer-reviewed studies involving 376 participants, researched for Vision & Eye Health, Skin Health & Anti-ageing, Immune Function & Epithelial Integrity.
Evidence at a Glance
Strength is scored by study design, sample size, study type, and outcomes
Vision & Eye Health
WeakSkin Health & Anti-ageing
ModerateImmune Function & Epithelial Integrity
WeakResearch Visualised
Visual breakdown of the clinical data.
Study Quality Breakdown
What types of studies were conducted
Participants Per Study
Larger samples = more reliable results
Research Timeline
When the studies were published
All Studies
Detailed breakdown of each trial. Click to expand.
Vision & Eye Health
To evaluate low-dose retinol supplementation on retinal function in AMD eyes without reticular pseudodrusen.
Study Type
Clinical study
Purpose
To evaluate low-dose retinol supplementation on retinal function in AMD eyes without reticular pseudodrusen.
Dose
16,000 IU/day vitamin A (retinol)
Participants
AMD patients (with and without reticular pseudodrusen)
Duration
12 months
Results
Vitamin A supplementation partially overcame pathophysiological changes in AMD eyes without pseudodrusen. Improvements in rod function and dark adaptation were observed. The pseudodrusen group did not improve, suggesting structural impediments.
How They Measured It
Full-field electroretinography, dark adaptation, cone and rod function
To review the essential roles of vitamin A in vision, cellular differentiation, and immune function.
Study Type
Reference review
Purpose
To review the essential roles of vitamin A in vision, cellular differentiation, and immune function.
Dose
Various
Participants
Review
Duration
Various
Results
Vitamin A is essential for rhodopsin synthesis (night vision), epithelial integrity, immune function, and gene regulation via retinoic acid receptors. Deficiency causes night blindness and increased infection susceptibility.
How They Measured It
Biochemical and clinical review of vitamin A functions and clinical deficiency outcomes
Skin Health & Anti-ageing
To review the evidence for over-the-counter retinol products in the improvement of facial skin ageing.
Study Type
Systematic review of RCTs
Purpose
To review the evidence for over-the-counter retinol products in the improvement of facial skin ageing.
Dose
Topical retinol (0.1-1%) in OTC formulations
Participants
Systematic review across eligible RCTs
Duration
12-24 weeks
Results
Retinol products significantly reduced facial wrinkles, improved skin texture, and reduced photo-ageing signs vs vehicle control. Topical retinol efficacy is lower than prescription tretinoin but with fewer adverse effects.
How They Measured It
Skin wrinkle reduction, skin texture, firmness, and photodamage scores across RCTs
To assess whether vitamin A (retinyl palmitate) supplementation improves serum retinol and retinol-binding protein status.
Study Type
Randomised, double-blind, placebo-controlled
Purpose
To assess whether vitamin A (retinyl palmitate) supplementation improves serum retinol and retinol-binding protein status.
Dose
Various retinyl palmitate supplementation regimens
Participants
376 adults
Duration
Various
Results
Vitamin A supplementation as retinyl palmitate significantly increased serum retinol and RBP concentrations dose-dependently. Effective at correcting suboptimal vitamin A status.
How They Measured It
Serum retinol, retinol-binding protein (RBP), liver enzyme tests (safety)
Immune Function & Epithelial Integrity
To review the role of vitamin A/retinol in maintaining pluripotency of stem cells and immune function.
Study Type
Mechanistic review
Purpose
To review the role of vitamin A/retinol in maintaining pluripotency of stem cells and immune function.
Dose
Various
Participants
Review
Duration
Various
Results
Vitamin A/retinol is essential for immune cell differentiation, particularly regulatory T-cells and mucosal immunity. Retinoic acid maintains stem cell pluripotency and epithelial cell integrity, with implications for skin health and systemic immune function.
How They Measured It
Review of retinoic acid receptor signalling, T-cell differentiation, stem cell pluripotency
Frequently Asked Questions
Common questions about Vitamin A (Retinol) research
There are currently 5 peer-reviewed studies on Vitamin A (Retinol) (Retinol / Retinyl Palmitate / Retinoic Acid (Preformed Vitamin A)), involving 376 total participants. Research covers Vision & night blindness, Immune function, Skin health & anti-ageing and 1 more areas. The overall evidence strength is rated as Moderate.
The evidence is currently rated as "Moderate Evidence". This rating is based on study design quality (randomisation, blinding, placebo controls), sample sizes, study types (2 human studies), and reported outcomes.
Vitamin A (Retinol) has been researched for: Vision & night blindness, Immune function, Skin health & anti-ageing, Epithelial integrity. Each area has its own body of evidence which you can explore in the study breakdowns above.
Yes, 2 out of 5 studies are human trials. Human trials carry more weight in our evidence scoring system.
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