NutriStack
Tretinoin Oral and Vitamin A, contraindicated.
Oral tretinoin is all-trans retinoic acid, an active vitamin A metabolite used systemically for acute promyelocytic leukemia. Adding preformed vitamin A supplements can intensify retinoid toxicity, including headache, mucocutaneous toxicity, liver abnormalities, lipid changes, and teratogenic risk. This is not a timing problem because both exposures converge on systemic retinoid signaling.
One pair, every claim cited. The two substances, the type, the mechanism, the recommendation, and the primary literature.
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What the row says.
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At a glance
- Substances
- Tretinoin Oral and Vitamin A
- Pair type
- Contraindicated
- Evidence (highest tier)
- Strong
- Source citations
- 2 sources
- Stack Score effect
- −25 to your Stack Score (per scored contraindication row).
- Scope
- Supplement × Prescription
- Last verified
- May 30, 2026
Contraindicated · Strong evidence
Contraindicated
What is happening. Oral tretinoin is all-trans retinoic acid, an active vitamin A metabolite used systemically for acute promyelocytic leukemia. Adding preformed vitamin A supplements can intensify retinoid toxicity, including headache, mucocutaneous toxicity, liver abnormalities, lipid changes, and teratogenic risk. This is not a timing problem because both exposures converge on systemic retinoid signaling.
Mechanism. Tretinoin is all-trans retinoic acid and directly activates retinoic acid receptors. Preformed vitamin A can be metabolized into active retinoids, increasing the total retinoid burden and the risk of hypervitaminosis A-like toxicity.
Recommendation. Do not take vitamin A supplements, cod liver oil, or high-retinol multivitamins during oral tretinoin therapy unless your oncology team explicitly prescribes them. Bring all supplements to medication reconciliation. Report severe headache, vision changes, abdominal pain, jaundice, or pregnancy exposure immediately.
Sources (2)
- Kamm JJ. Toxicology, carcinogenicity, and teratogenicity of some orally administered retinoids. J Am Acad Dermatol. 1982;6(4 Pt 2 Suppl):652-659. PMID 7040511
- Carazo A, Macakova K, Matousova K, et al. Vitamin A Update: Forms, Sources, Kinetics, Detection, Function, Deficiency, Therapeutic Use and Toxicity. Nutrients. 2021;13(5):1703. PMID 34069881
Stack Score
How this pair moves the number.
Effect on the composite score
If both Tretinoin Oral and Vitamin A are in the same stack, this pair applies −25 to your Stack Score (per scored contraindication row).
The full algorithm, the clamping rules, and four worked stacks are documented at /methodology/stack-score.
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