Vitamin A
Also known as: Retinol, Retinyl palmitate, Retinyl acetate, Beta-carotene, Provitamin A, All-trans retinol, Vitamin A acetate, Vitamin A palmitate
This ingredient is classified as unclassified risk (GIRI score: 3.5/10).
Safety Profile
Known Safety Concerns
- Teratogenic at >3,000 µg RAE/day (preformed Retinol) — NOT for pregnancy; hypervitaminosis A at chronic high doses; smokers caution with beta-carotene
Contraindications
- Teratogenic at >3,000 µg RAE/day (preformed Retinol) — NOT for pregnancy; hypervitaminosis A at chronic high doses; smokers caution with beta-carotene
Interactions
Information not yet available for this ingredient profile.
Evidence and Scientific Findings
Ingredient Overview
Vitamin A encompasses preformed retinoids (Retinol, Retinyl palmitate, Retinyl acetate — from animal sources and synthetic forms) and provitamin A carotenoids (Beta-carotene, Alpha-carotene, Beta-cryptoxanthin — from plant sources, converted to retinol in the body). Functions include vision (11-cis-retinal is the chromophore of rhodopsin in rod photoreceptors), immune function (T-cell differentiation, NK cell activity), skin cell differentiation (keratinocyte regulation), epithelial integrity, and embryonic development. CRITICAL SAFETY — Preformed Retinol: teratogenic at doses above 3,000 µg RAE/day (10,000 IU/day) in pregnancy — causes birth defects (craniofacial, cardiac, CNS malformations). EU recommends pregnant women avoid Retinol supplements. EFSA UL for adults: 3,000 µg RAE/day. Chronic hypervitaminosis A (prolonged intake >10,000 IU/day) causes liver toxicity, bone pain, alopecia, and increased fracture risk (bone resorption). Beta-carotene is substantially safer — no teratogenicity risk; body regulates conversion rate. Caution: pharmacological Beta-carotene doses in smokers associated with increased lung cancer risk (CARET trial). Drug interactions: concurrent retinoid medications (isotretinoin, tretinoin, acitretin) — additive toxicity. Tetracyclines increase intracranial pressure risk with Vitamin A. Form must be confirmed from product label (Retinol vs Beta-carotene).
Biological and Chemical Classification
Information not yet available for this ingredient profile.
Mechanism of Action
Information not yet available for this ingredient profile.
Clinical Evidence of Effectiveness
Information not yet available for this ingredient profile.
Pharmacokinetics
Information not yet available for this ingredient profile.
Recommended Dosage
Information not yet available for this ingredient profile.
SETI — Scientific Evidence Transparency Index
Executive Summary — Ingredient Assessment
- 10 studies reviewed
- 0 high-quality studies (meta-analysis or RCT)
- Main clinical benefit observed: Vitamins & Minerals
- Evidence consistency: High consistency across studies (100%)
- Teratogenic at >3,000 µg RAE/day (preformed Retinol) — NOT for pregnancy; hypervitaminosis A at chronic high doses; smokers caution with beta-carotene
The available scientific evidence for Vitamin A indicates notable safety signals that warrant caution. Use should be considered carefully and monitored, particularly in sensitive populations or alongside other medications.
Total SETI Score
High risk| Evidence quality | 10/40 |
| Evidence consistency | 20/20 |
| Safety signals | 0/20 |
| Study recency | 10/10 |
| Evidence transparency | 10/10 |
Evidence Summary
- 10 studies reviewed
- 0 high-quality studies (meta-analysis or systematic review)
- 0 studies identified benefits or no safety concern (GREEN)
- 10 studies reported limited or advisory safety evidence (YELLOW)
Evidence Policy
Only peer-reviewed scientific literature indexed in PubMed or comparable databases is included in this evaluation. Commercial websites, blogs, and marketing materials are excluded. All references include direct traceable links to source documents.
Last updated: 06 აპრ 2026, 12:09
Evidence Distribution
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Observational / other LOW evidence YELLOWPost-harvest losses of perishable vegetables and their contribution to household dietary gaps in Kamonyi District, Rwanda. ↗Fabien G et al.. Post-harvest losses of perishable vegetables and their contribution to household dietary gaps in Kamonyi District, Rwanda.. BMC Public Health. 2026. PMID:41937122.PMID 41937122 ↗Journal BMC Public HealthYear 2026Study type Observational / otherEvidence strength LOW evidencePubMed link https://pubmed.ncbi.nlm.nih.gov/41937122/
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Observational / other LOW evidence YELLOWEffects of neonatal Vitamin A supplementation on response to vaccinations in early infancy. ↗Stephensen CB et al.. Effects of neonatal Vitamin A supplementation on response to vaccinations in early infancy.. Vaccine. 2026. PMID:41936264.PMID 41936264 ↗Journal VaccineYear 2026Study type Observational / otherEvidence strength LOW evidencePubMed link https://pubmed.ncbi.nlm.nih.gov/41936264/
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Observational / other LOW evidence YELLOWVitamin A deficiency induces sex-specific reward processing alterations through a dysregulation of the mesolimbic dopamine transmission in mice. ↗Couty P et al.. Vitamin A deficiency induces sex-specific reward processing alterations through a dysregulation of the mesolimbic dopamine transmission in mice.. Neuropsychopharmacology. 2026. PMID:41935220.PMID 41935220 ↗Journal NeuropsychopharmacologyYear 2026Study type Observational / otherEvidence strength LOW evidencePubMed link https://pubmed.ncbi.nlm.nih.gov/41935220/
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Observational / other LOW evidence YELLOWApplication of machine learning algorithm for predicting acute malnutrition among under 5 children in east Africa using recent DHS. ↗Feleke HG et al.. Application of machine learning algorithm for predicting acute malnutrition among under 5 children in east Africa using recent DHS.. Sci Rep. 2026. PMID:41935198.PMID 41935198 ↗Journal Sci RepYear 2026Study type Observational / otherEvidence strength LOW evidencePubMed link https://pubmed.ncbi.nlm.nih.gov/41935198/
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Observational / other LOW evidence YELLOWMaternal nutrition as a key determinant of placental and developing blood-brain barrier xenobiotic protective functions. ↗Connor KL et al.. Maternal nutrition as a key determinant of placental and developing blood-brain barrier xenobiotic protective functions.. J Physiol. 2026. PMID:41935021.PMID 41935021 ↗Journal J PhysiolYear 2026Study type Observational / otherEvidence strength LOW evidencePubMed link https://pubmed.ncbi.nlm.nih.gov/41935021/
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Observational / other LOW evidence YELLOWSaliva as a Matrix for Primary Care: Feasibility and Scoping of its Use for Assessment of Nutrition and Inflammation. ↗Fahim SM et al.. Saliva as a Matrix for Primary Care: Feasibility and Scoping of its Use for Assessment of Nutrition and Inflammation.. Adv Nutr. 2026. PMID:41933704.PMID 41933704 ↗Journal Adv NutrYear 2026Study type Observational / otherEvidence strength LOW evidencePubMed link https://pubmed.ncbi.nlm.nih.gov/41933704/
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Observational / other LOW evidence YELLOWAdding small quantity lipid-based nutrient supplements to an enhanced homestead food production program improves child hemoglobin, iron and vitamin A status in… ↗Bliznashka L et al.. Adding small quantity lipid-based nutrient supplements to an enhanced homestead food production program improves child hemoglobin, iron and vitamin A status in rural Burkina Faso: a cluster randomized controlled trial.. J Nutr. 2026. PMID:41932365.PMID 41932365 ↗Journal J NutrYear 2026Study type Observational / otherEvidence strength LOW evidencePubMed link https://pubmed.ncbi.nlm.nih.gov/41932365/
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Observational / other LOW evidence YELLOWPerception and acceptance of micronutrient-Fortified Bouillon among Non-Index Household Members: A longitudinal sub-study nested within a randomized trial in Northern Ghana. ↗Kyereh FK et al.. Perception and acceptance of micronutrient-Fortified Bouillon among Non-Index Household Members: A longitudinal sub-study nested within a randomized trial in Northern Ghana.. PLoS One. 2026. PMID:41931601.PMID 41931601 ↗Journal PLoS OneYear 2026Study type Observational / otherEvidence strength LOW evidencePubMed link https://pubmed.ncbi.nlm.nih.gov/41931601/
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Observational / other LOW evidence YELLOWAll-trans retinoic acid modulates proliferation and apoptosis of secondary hair follicle-dermal papilla cells in cashmere goats via the TGF-u03b22/Smad2/3 pathway. ↗Gao Y et al.. All-trans retinoic acid modulates proliferation and apoptosis of secondary hair follicle-dermal papilla cells in cashmere goats via the TGF-u03b22/Smad2/3 pathway.. Front Vet Sci. 2026. PMID:41929273.PMID 41929273 ↗Journal Front Vet SciYear 2026Study type Observational / otherEvidence strength LOW evidencePubMed link https://pubmed.ncbi.nlm.nih.gov/41929273/
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Observational / other LOW evidence YELLOWThe Impact of Elexacaftor/Tezacaftor/Ivacaftor on Fat-Soluble Vitamin Status and Supplementation in a Pediatric Cystic Fibrosis Cohort. ↗Kimber F et al.. The Impact of Elexacaftor/Tezacaftor/Ivacaftor on Fat-Soluble Vitamin Status and Supplementation in a Pediatric Cystic Fibrosis Cohort.. Pediatr Pulmonol. 2026. PMID:41928655.PMID 41928655 ↗Journal Pediatr PulmonolYear 2026Study type Observational / otherEvidence strength LOW evidencePubMed link https://pubmed.ncbi.nlm.nih.gov/41928655/
Score Transparency
0 of 10 approved references (score saturates at 10). More peer-reviewed studies = stronger evidence base.
Method: Q = number of approved references ÷ 10 (capped at 1.0)
Limited — mostly case reports or animal studies
Method: L = mean study-level weight across approved references. Level 1 (meta-analysis / systematic review) = 1.0; Level 2 (RCT) = 0.8; Level 3 (cohort/case-control) = 0.6; Level 4 (case report) = 0.4; Level 5 (animal / in-vitro) = 0.2.
Mixed or neutral — roughly equal benefit and risk signals
Method: D = (sum of risk-scored references − sum of benefit-scored references) ÷ total evidence score, then scaled from [−1, 1] to [0, 1]. 0.0 = pure benefit; 0.5 = neutral; 1.0 = pure risk.
One or more monitoring-level safety signals active
Method: S = 0.5 (neutral baseline) + sum of active signal severity deltas ÷ 10. Severity deltas: Critical = +2.0, High = +1.5, Moderate = +1.0, Low = +0.5. Capped at 1.0.
Final GIRI Score for Vitamin A. Risk level thresholds: Low 0–3.0 · Moderate 3.0–5.5 · High 5.5–7.5 · Critical 7.5–10.
Full methodology & data sources
The GIRI Score is computed entirely from structured data — no editorial scoring or subjective weighting is applied at any step.
- References: Only approved references are counted. Each reference is assigned an evidence level (L1–L5) and a direction (risk / neutral / benefit) by the reference manager or AI classifier.
- Safety Signals: Sourced from regulatory agencies (FDA, EMA, Health Canada, TGA, and others) and pharmacovigilance databases. Only active signals count toward the score.
- Formula version: GIRI Score v3.7.0 — Q × L × D × S × 10.
- Limitations: The score reflects published evidence and recorded signals as of the last update date. It is not a clinical risk assessment and should not replace advice from a qualified healthcare professional.
Risk Level Classification
Based on available regulatory signals and scientific evidence, this ingredient presents a moderate safety concern. Caution is advised, particularly at high doses or in sensitive populations.
0–3.0
3.0–5.5
5.5–7.5
7.5–10
The score pin shows exactly where this ingredient falls on the fixed risk scale.
What drove the Moderate classification for Vitamin A
A score of 3.5 places this ingredient in the Moderate band. Thresholds: Low 0–3.0 · Moderate 3.0–5.5 · High 5.5–7.5 · Critical 7.5–10.
0 approved references.
Limited — mostly case reports or animal studies (Level 4–5).
Neutral or mixed — benefit and risk signals roughly balanced.
No active signals — S component is at neutral baseline (0.5), contributing no extra risk weight.
No major regulatory restrictions or advisories recorded across monitored jurisdictions (FDA, EMA, Health Canada, TGA, and others).
How are the Low / Moderate / High / Critical thresholds defined?
The four risk levels are fixed score bands. A score is assigned to exactly one level based on where it falls:
| Level | Score | Meaning |
|---|---|---|
| LOW | 0.0 – 2.9 | Sparse or predominantly beneficial evidence. No active safety alerts. |
| MODERATE | 3.0 – 5.4 | Mixed signals — some risk alongside benefit. Caution at high doses or in sensitive groups. |
| HIGH | 5.5 – 7.4 | Multiple studies or regulatory alerts documenting adverse effects. Professional oversight recommended. |
| CRITICAL | 7.5 – 10 | Regulatory restrictions in one or more major jurisdictions. Serious documented harm. Avoid without specialist supervision. |
Thresholds are fixed constants (GIRI_Score_Utils::LEVEL_THRESHOLDS). They do not change per ingredient and are never subject to editorial adjustment.