Vitamin A

Pronunciation: VY-tuh-min ay.

Generic name: vitamin A
Drug class: Essential fat-soluble vitamin
Form: Dietary supplement forms were not established in the reviewed sources
Route: Oral intake from food or dietary supplements
Legal status: Available as a dietary supplement and naturally occurring in food; not a prescription medicine in its normal-dose supplement form

Availability and supply rules vary by country

Trade names by country: United States

What vitamin A is and how it works

Vitamin A is an essential fat-soluble vitamin. It includes retinol and provitamin A carotenoids and is available from food and as a dietary supplement. (3) (1) (2)

Vitamin A is needed for retinal photoreceptor function and night vision, healthy skin and linings of the lungs, intestine, and urinary tract, and protection against infections. Both deficiency and excessive intake can be harmful.

Mechanism of action: how vitamin A works

Vitamin A is necessary for retinal photoreceptor function and night vision and helps maintain skin and the linings of the lungs, intestine, and urinary tract. Retinoids are described as altering gene expression; during pregnancy, oral retinoid exposure can disrupt neural crest cell migration and axial patterning. (1) (2) (3)

What vitamin A is used for

Nutritional intake

Vitamin A is an essential nutrient obtained from food and may also be obtained from dietary supplements. (3)

Vitamin A deficiency

Vitamin A deficiency can impair night vision, eye health, immune function, and other tissues. The reviewed sources did not establish a self-treatment dose or a country-specific supplementation regimen for deficiency. (3)

Before taking vitamin A

Do not take / not appropriate for

Additional vitamin A supplementation alongside systemic retinoids, including isotretinoin, acitretin, or bexarotene, requires prescriber or pharmacist assessment because of additive toxicity risk. (Systemic retinoid use) (2)
Pregnancy requires clinician-led assessment before vitamin A supplementation because teratogenic effects have been reported with high intake and no safe threshold for oral retinoid exposure during pregnancy has been established. (Pregnancy) (2)

Tell your clinician about

Pregnancy, plans for pregnancy, or breastfeeding.
Any liver disease, hyperlipidemia, or high alcohol intake.
Use of a systemic retinoid, including isotretinoin, acitretin, or bexarotene.
All vitamin A-containing supplements and other supplements, foods, or medicines being used.
Symptoms that could suggest excess vitamin A, including severe headache, blurred vision, nausea, dizziness, muscle aches, or coordination problems.
Difficulty seeing in low light, dry eyes, recurrent infections, or other concerns that could suggest vitamin A deficiency.

(1) (2) (3)

How to take vitamin A

Use vitamin A from food or a supplement only in a manner agreed with a clinician, dietitian, or pharmacist when supplementation is being considered.
The reviewed US-oriented figures list an adult Recommended Dietary Allowance of 900 mcg retinol activity equivalents (RAE) daily for men and 700 mcg RAE daily for women.
The reviewed sources list an adult tolerable upper intake level of 3,000 mcg RAE daily, equivalent to 10,000 IU, for preformed vitamin A.
Do not alter a clinician-directed supplement or retinoid treatment plan yourself; ask the responsible clinician or pharmacist to assess the total intake and safety.

(1) (2)

Procedures and treatment changes

Tell the treating team before surgery, procedures, or any medicine change. Do not alter treatment without the responsible clinician. (1) (2) (3)

Missed dose

The reviewed sources did not provide missed-dose instructions for vitamin A supplements. Ask a pharmacist or clinician for advice rather than taking an extra dose.

Overdose

A suspected excessive vitamin A exposure needs urgent assessment by a clinician, poison-information service, or emergency service as appropriate. Acute toxicity may occur within days to weeks after one or a few very high doses and can cause severe headache, blurred vision, nausea, dizziness, aching muscles, and coordination problems. (1) (2)

Side effects

The reviewed sources focused on effects of vitamin A toxicity rather than a complete side-effect profile for normal-dose supplements. Toxicity risk depends on the form, amount, duration of intake, and individual susceptibility.

Symptoms of acute excessive intake

What to notice: Severe headache, blurred vision, nausea, dizziness, aching muscles, or coordination problems.

What to do: Seek prompt medical advice if these symptoms occur after possible high vitamin A intake. (1) (2)

Possible chronic vitamin A toxicity

What to notice: Possible toxicity after prolonged supratherapeutic intake, generally described as 25,000 to 50,000 IU daily over months; lower doses may cause toxicity in susceptible individuals.

What to do: Contact a clinician or pharmacist promptly for assessment of all vitamin A sources and relevant medicines. (2)

Possible vitamin A deficiency

What to notice: Difficulty seeing in low light, dry whites of the eyes or corneas with reduced tear production, recurrent chest or throat infections, or worsening vision.

What to do: Arrange clinical assessment. Severe untreated deficiency can cause vision loss and blindness. (3)

Serious warnings

Acute vitamin A toxicity — urgent

Symptoms: Severe headache, blurred vision, nausea, dizziness, aching muscles, and coordination problems after a possible very high intake.

Action: Seek urgent medical assessment or contact a poison-information service. Provide the product name, amount, and timing if known. (1) (2)

Pregnancy-related teratogenic risk — urgent

Symptoms: There may be no immediate symptoms. High vitamin A or oral retinoid exposure in pregnancy has been associated with fetal malformations.

Action: Contact the relevant maternity clinician, prescriber, or urgent medical service promptly for individual assessment of the exposure. (2)

Severe vitamin A deficiency — urgent

Symptoms: Progressive eye dryness, worsening night vision, vision loss, or blindness.

Action: Seek prompt medical assessment. Severe untreated deficiency can affect vision and other tissues. (3)

Interactions

Medicine or test	Effect	Action
Systemic retinoids	Systemic retinoids, including isotretinoin, acitretin, and bexarotene, can have additive toxicity with vitamin A supplementation.	Give the prescriber and pharmacist a complete list of retinoid and supplement products so they can assess safety. (2)
Topical retinoids	Topical retinoids have minimal systemic absorption and are considered unlikely to cause systemic toxicity under normal use in the reviewed source.	Ask a clinician or pharmacist to assess individual products and total exposure. (2)
Other medicines	No specific interaction data beyond retinoids were confirmed in this research pass.	Ask a pharmacist or clinician to review all medicines and supplements before adding vitamin A.

Pregnancy, breastfeeding, kidney/liver function, age

Pregnancy

Pregnant women are at higher risk of vitamin A toxicity. Teratogenic effects have been reported at doses as low as 25,000 IU daily, and no safe threshold for oral retinoid exposure during pregnancy has been established. Pregnancy intake figures in the reviewed source were 750 to 770 RAE daily, equivalent to 2,500 to 2,567 IU, but these are not a personalised supplement plan. (2)

Breastfeeding

The reviewed source lists lactation intake figures of 1,200 to 1,300 RAE daily, equivalent to 4,000 to 4,333 IU. Individual supplementation decisions require clinician or dietitian advice. (2)

Infants and children

Infants and children are at higher risk of toxicity because of smaller body size and lower tolerance. The reviewed sources did not provide a pediatric dosing table by age band. An acute toxicity threshold of 350,000 IU was reported for infants. (2)

Liver disease, hyperlipidemia, high alcohol intake, and older age

These groups were identified as being at higher risk of vitamin A toxicity. Supplement use requires individual clinical assessment. (2)

Monitoring

Before starting

Clarify whether supplementation is needed and identify all dietary supplements, medicines, and potential vitamin A sources.
Assess pregnancy status or pregnancy plans, liver disease, hyperlipidemia, alcohol intake, age, and systemic retinoid use.
Use country-specific professional guidance where available; no UK/EU or other non-US regulatory guidance was reviewed in this research pass.

During treatment

Review the amount and form of vitamin A consumed, including possible preformed vitamin A and retinoid exposure.
Assess for symptoms of acute or chronic toxicity and for symptoms that could suggest deficiency.
Reassess any clinician-directed supplementation plan rather than making independent dose changes.

(1) (2) (3)

Storage

Product-specific storage requirements for vitamin A supplements were not established in the reviewed sources. Follow the exact product packaging and ask a pharmacist if storage conditions are uncertain.

Professional information

Clinician-facing context only. The reviewed material does not establish a product-specific supplementation regimen, pediatric dose table, renal adjustment, or non-US regulatory guidance.

United States-oriented figures from reviewed sources

Indication: General nutritional intake

Dose summary: Reported adult RDA: 900 mcg RAE daily for men and 700 mcg RAE daily for women. The adult tolerable upper intake level for preformed vitamin A was 3,000 mcg RAE daily, also reported as 10,000 IU. Pregnancy figures reported were 750 to 770 RAE daily (2,500 to 2,567 IU), and lactation figures were 1,200 to 1,300 RAE daily (4,000 to 4,333 IU). These figures are not a patient-specific treatment or supplementation prescription.

Renal context: Renal-impairment dosing was not established in the reviewed sources. (1) (2)

Other regions

Indication: Vitamin A supplementation

Dose summary: Country-specific regulatory guidance outside the US was not reviewed in this research pass and remains unresolved.

Renal context: Renal-impairment guidance remains unresolved from the reviewed sources.

Mechanism of action

Hepatic guidance

Liver disease was identified as a factor associated with higher toxicity risk. Specific hepatic-impairment dosing was not established in the reviewed sources.

Overdose note

Acute toxicity was reported after more than 2 million IU in adults or 350,000 IU in infants, approximately 25,000 IU/kg body weight. Chronic toxicity was generally described with 25,000 to 50,000 IU daily over months, although lower doses may cause toxicity in susceptible individuals. Management details should be directed by a clinician or poison-information service. (1) (2) (3)

Frequently asked questions

What is the adult recommended intake of vitamin A?

The reviewed US-oriented sources report 900 mcg RAE daily for adult men and 700 mcg RAE daily for adult women. These are general nutritional reference values, not an individual supplement prescription. (1) (2)

Can too much vitamin A be harmful?

Yes. Excess preformed vitamin A can cause acute or chronic toxicity. Acute symptoms can include severe headache, blurred vision, nausea, dizziness, muscle aches, and coordination problems. The reviewed adult upper intake level for preformed vitamin A is 3,000 mcg RAE daily, or 10,000 IU. (1) (2)

Can I take vitamin A with isotretinoin or another retinoid?

Systemic retinoids such as isotretinoin, acitretin, and bexarotene can have additive toxicity with vitamin A supplements. Ask the prescriber or pharmacist to review the products before adding a supplement. (2)

What are possible signs of vitamin A deficiency?

An early sign is night blindness, meaning difficulty seeing in low light despite normal vision in adequate light. More severe deficiency can cause eye dryness, reduced tear production, infections, vision loss, and blindness. (3)

What is the mechanism of action of vitamin A?

What is the generic name of Vitamin A?

The generic name is vitamin A. (1) (2) (3)

What class of drug is vitamin A?

Vitamin A is classed as: Essential fat-soluble vitamin. (1) (2) (3)

References

Vitamin A and Carotenoids — Fact Sheet for Health Professionals (as summarised by WebSearch engine)NIH Office of Dietary Supplements · United States · accessed 2026-08-05 · source 1
Vitamin A ToxicityStatPearls / National Center for Biotechnology Information, U.S. National Library of Medicine · United States · accessed 2026-08-05 · source 2
Vitamin A Deficiency (as summarised by WebSearch engine)Cleveland Clinic · United States · accessed 2026-08-05 · source 3

Brand names by country

Single-ingredient vitamin A names are shown separately by country. Product availability, strengths, and supply rules can change; combination products are not included here.

Priority countries

United States

AQUASOL A Parenteral15 mg/mL · rising pharma holdings, inc.

View brands in additional countries.