What is the recommended dose of Vitamin A?

- **RDA:** 700-900mcg RAE/day (2,333-3,000 IU) - **Upper limit:** 3,000mcg RAE/day (10,000 IU) preformed vitamin A - **Beta-carotene:** 6-15mg/day (converts to vitamin A as needed — body self-regul...

Is Vitamin A safe to take daily?

Vitamin A is rated "Prescription Interactions" based on clinical evidence. Always consult your healthcare provider before starting any supplement.

Does Vitamin A interact with any medications?

Vitamin A has 6 known drug interactions, including interactions with Retinoids (isotretinoin/Accutane), Warfarin, Tetracyclines. Check with your doctor before combining with prescription medications.

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Ingredient Research

Graded against 173,636 supplements + 177 published clinical interactions, sourced from PubMed, FDA CAERS, openFDA, NIH DSLD

Vitamin A

STRONG EVIDENCEVitaminLast updated April 2026

AVELOR SUMMARY

Vitamin A is essential for vision, immune function, reproduction, and cellular communication. Our research distinguishes between preformed vitamin A (retinol — from animal sources) and provitamin A (beta-carotene — from plants). The critical safety concern: preformed vitamin A is teratogenic at doses >10,000 IU/day during pregnancy and hepatotoxic with chronic high-dose supplementation. Beta-carotene INCREASES lung cancer risk in smokers. This is one supplement where excess is genuinely dangerous.

EVIDENCE GRADES

Deficiency correction (night blindness, xerophthalmia)Definitive — established medicine

Immune function (deficient populations)Strong — WHO supplementation programs

Skin health (retinoids — prescription)Strong — acne, photoaging (topical/oral Rx)

Lung cancer risk (beta-carotene in smokers)ATBC and CARET trials: 18-28% INCREASED lung cancer (PMID: 8127329)

⚠️ HARM

Prostate cancer risk (high retinol)Observational association with increased risk

⚠️ CONCERN

OPTIMAL DOSAGE

RDA: 700-900mcg RAE/day (2,333-3,000 IU)
Upper limit: 3,000mcg RAE/day (10,000 IU) preformed vitamin A
Beta-carotene: 6-15mg/day (converts to vitamin A as needed — body self-regulates)
Pregnancy: 770mcg RAE/day — do NOT exceed 10,000 IU preformed vitamin A
Most multivitamins provide 100% DV — additional supplementation rarely needed

Scan a supplement containing Vitamin A

DRUG INTERACTIONS

Retinoids (isotretinoin/Accutane)Severe

Additive vitamin A toxicity — hypervitaminosis A risk

WarfarinModerate

High-dose vitamin A may increase bleeding risk

TetracyclinesSevere

Additive intracranial pressure (pseudotumor cerebri)

Hepatotoxic drugsModerate

Chronic vitamin A is hepatotoxic; additive liver stress

OrlistatModerate

Reduces fat-soluble vitamin absorption including vitamin A

CholestyramineModerate

Reduces absorption

SAFETY PROFILE

Drug Interactions

⚠️ Toxicity Warnings

Acute toxicity (>100,000 IU single dose): Nausea, vomiting, vertigo, blurred vision, intracranial pressure
Chronic toxicity (>25,000 IU/day for months): Liver damage, bone loss, headache, skin peeling, hair loss
Teratogenicity: Preformed vitamin A >10,000 IU/day during pregnancy causes birth defects — neural crest malformations (PMID: 7570449)
Smokers + beta-carotene: 20-30mg/day beta-carotene INCREASED lung cancer by 18-28% in two large trials (ATBC, CARET)

Pregnancy & Lactation

CRITICAL: Do NOT exceed 10,000 IU (3,000mcg) preformed vitamin A during pregnancy
Beta-carotene does NOT carry teratogenic risk (self-regulated conversion)
Prenatal vitamins should use beta-carotene or mixed carotenoids rather than retinol

WADA Status

Not Prohibited

HOW AVELOR SCORES THIS

Products >10,000 IU preformed vitamin A: automatic upper limit warning

Pregnancy screen: products with >3,000mcg retinol trigger teratogenicity alert

Smoker screen: beta-carotene supplementation gets lung cancer risk warning

Isotretinoin/Accutane users: automatic CONTRAINDICATED flag

Beta-carotene from food sources vs supplements: note that supplement beta-carotene in smokers is harmful while dietary beta-carotene is not

Products using mixed carotenoids score better than high-dose retinol for general population

CLINICAL REFERENCES

Alpha-Tocopherol, Beta-Carotene Cancer Prevention Study Group. The effect of vitamin E and beta carotene on lung cancer (ATBC trial).

PMID: 8127329

Omenn GS et al. Effects of a combination of beta carotene and vitamin A on lung cancer (CARET trial).

PMID: 8602180

Rothman KJ et al. Teratogenicity of high vitamin A intake. *N Engl J Med.* 1995.

(1995). PMID: 7570449

Penniston KL, Tanumihardjo SA. The acute and chronic toxic effects of vitamin A.

PMID: 16968850

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Scan Your Vitamin A Supplement Browse all ingredients

Independently graded against 173,636 indexed supplements with 177 published clinical interactions, sourced from PubMed, FDA CAERS, openFDA, and NIH DSLD | Last updated: April 2026

Not medical advice. Based on published clinical research and systematic reviews.

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Browse All 834 Ingredients Browse All 20 Conditions

Ingredient Research

Graded against 173,636 supplements + 177 published clinical interactions, sourced from PubMed, FDA CAERS, openFDA, NIH DSLD

Vitamin A

STRONG EVIDENCEVitaminLast updated April 2026

AVELOR SUMMARY

EVIDENCE GRADES

Deficiency correction (night blindness, xerophthalmia)Definitive — established medicine

Immune function (deficient populations)Strong — WHO supplementation programs

Skin health (retinoids — prescription)Strong — acne, photoaging (topical/oral Rx)

Lung cancer risk (beta-carotene in smokers)ATBC and CARET trials: 18-28% INCREASED lung cancer (PMID: 8127329)

⚠️ HARM

Prostate cancer risk (high retinol)Observational association with increased risk

⚠️ CONCERN

OPTIMAL DOSAGE

RDA: 700-900mcg RAE/day (2,333-3,000 IU)
Upper limit: 3,000mcg RAE/day (10,000 IU) preformed vitamin A
Beta-carotene: 6-15mg/day (converts to vitamin A as needed — body self-regulates)
Pregnancy: 770mcg RAE/day — do NOT exceed 10,000 IU preformed vitamin A
Most multivitamins provide 100% DV — additional supplementation rarely needed

Scan a supplement containing Vitamin A

DRUG INTERACTIONS

Retinoids (isotretinoin/Accutane)Severe

Additive vitamin A toxicity — hypervitaminosis A risk

WarfarinModerate

High-dose vitamin A may increase bleeding risk

TetracyclinesSevere

Additive intracranial pressure (pseudotumor cerebri)

Hepatotoxic drugsModerate

Chronic vitamin A is hepatotoxic; additive liver stress

OrlistatModerate

Reduces fat-soluble vitamin absorption including vitamin A

CholestyramineModerate

Reduces absorption

SAFETY PROFILE

Drug Interactions

⚠️ Toxicity Warnings

Acute toxicity (>100,000 IU single dose): Nausea, vomiting, vertigo, blurred vision, intracranial pressure
Chronic toxicity (>25,000 IU/day for months): Liver damage, bone loss, headache, skin peeling, hair loss
Teratogenicity: Preformed vitamin A >10,000 IU/day during pregnancy causes birth defects — neural crest malformations (PMID: 7570449)
Smokers + beta-carotene: 20-30mg/day beta-carotene INCREASED lung cancer by 18-28% in two large trials (ATBC, CARET)

Pregnancy & Lactation

CRITICAL: Do NOT exceed 10,000 IU (3,000mcg) preformed vitamin A during pregnancy
Beta-carotene does NOT carry teratogenic risk (self-regulated conversion)
Prenatal vitamins should use beta-carotene or mixed carotenoids rather than retinol

WADA Status

Not Prohibited

HOW AVELOR SCORES THIS

Products >10,000 IU preformed vitamin A: automatic upper limit warning

Pregnancy screen: products with >3,000mcg retinol trigger teratogenicity alert

Smoker screen: beta-carotene supplementation gets lung cancer risk warning

Isotretinoin/Accutane users: automatic CONTRAINDICATED flag

Beta-carotene from food sources vs supplements: note that supplement beta-carotene in smokers is harmful while dietary beta-carotene is not

Products using mixed carotenoids score better than high-dose retinol for general population

CLINICAL REFERENCES

Alpha-Tocopherol, Beta-Carotene Cancer Prevention Study Group. The effect of vitamin E and beta carotene on lung cancer (ATBC trial).

PMID: 8127329

Omenn GS et al. Effects of a combination of beta carotene and vitamin A on lung cancer (CARET trial).

PMID: 8602180

Rothman KJ et al. Teratogenicity of high vitamin A intake. *N Engl J Med.* 1995.

(1995). PMID: 7570449

Penniston KL, Tanumihardjo SA. The acute and chronic toxic effects of vitamin A.

PMID: 16968850

RELATED RESEARCH

Acerola Cherry

Amla

BiotinBiotin is a cofactor for five carboxylase enzymes critical to metabolism: pyruva

Amla

Scan Your Vitamin A Supplement Browse all ingredients

Independently graded against 173,636 indexed supplements with 177 published clinical interactions, sourced from PubMed, FDA CAERS, openFDA, and NIH DSLD | Last updated: April 2026

Not medical advice. Based on published clinical research and systematic reviews.

Discover More

Explore

Browse All 834 Ingredients Browse All 20 Conditions