Introduction

Vitamin A is a critical and essential nutrient for human eye health, immunity, reproduction, and normal growth and development. In addition, vitamin A helps the heart, lungs, and other organs work properly.

Vitamin A deficiency is a major nutritional deficiency worldwide, particularly among children, and pregnant and breastfeeding women in sub-Saharan Africa and South Asia. It causes growth and development deficits in children, vision loss and blindness and increased infection risk, especially diarrhea and measles, in developing countries.

Vitamin A deficiency is rare in the United States (U.S.) because most people get enough vitamin A from foods. The greater concern in the U.S. is getting too much vitamin A from diet and supplements.

This fact sheet reviews vitamin A requirements, and sources from food and supplements.

Food Sources

There are two sources of vitamin A in foods.

• Preformed vitamin A (retinol and retinyl esters), found in fish, organ meats, dairy products and eggs. Also included in fortified foods, such as breakfast cereals, dairy products, margarine, and some juices.
• Provitamin A carotenoids, found in green leafy and orange vegetables, fruits, and other plant-based products. Beta-carotene is the most common in food. The body changes beta-carotene into vitamin A.

Multivitamin Supplements

Most multivitamin supplements contain a mix of retinol (Vitamin A) and beta-carotene, which, as noted above, the body changes into vitamin A.

What Vitamin A Intakes Are Recommended

The recommended dietary allowance (RDA) for vitamin A differs according to the form consumed. The RDA uses retinol activity units (RAE) as a measurement to count the different bio-activities of retinol and provitamin A carotenoids in food.

The U.S. Food and Drug Administration (FDA) began requiring manufacturers to use new labeling requirements for manufacturers in 2020, measuring vitamin A in micrograms of RAE, and no longer using international units (IU).

The FDA developed percent Daily Values (DV) for nutrition facts and supplement labels to help consumers compare the nutrient content of food and dietary supplements, within the context of a total diet. DV’s are presented on supplement labels as a percentage, and are designed to help the comparison of a single serving of one product with another. The amount of vitamin A requirement depends on age and sex.

Can I Get Too Much Vitamin A?

It is possible to get too much vitamin A if dietary intake in foods is high, and a multivitamin or other supplements provide too much. Liver and cod liver oil are very high in vitamin A. Therefore, if you eat liver frequently, or use cod liver oil, make sure your supplements do not contain extra vitamin A.

Fat soluble vitamins, like vitamin A can lead to toxic levels because your body doesn’t excrete any excess; it is stored in the liver and fat tissues. The tolerable upper limit for vitamin A for children and adults is 3000 mcg RAE per day. Multivitamins typically contain 750-1000 mcg RAE; however, some may contain up to 3,000 mcg.

Check the label to make sure that most of the vitamin A in a multivitamin is in the form of beta-carotene (which is not associated with toxicity) rather than retinol or retinyl esters.

Single supplement vitamin A often contains around 3000 mcg.  Consumers should check supplement labels to determine if the vitamin A dose does not exceed 100% of the RDA.

Excessive intakes of beta-carotene (from plant sources) may result in yellowing of the skin, which is harmless and will subside when intakes are decreased.

Vitamin A Toxicity Can Be Acute or Chronic

Acute vitamin A toxicity

This happens most frequently when someone, usually a child, ingests a megadose of vitamin A from a supplement (over 100,000 RAE within a short period). It is a relatively rare occurrence.

Symptoms include:

• Headache;
• Dizziness;
• Rash;
• Fatigue;
• Irritability;
• Stomach pain, nausea and vomiting.

If vitamin A toxicity is suspected, caregivers should call poison control at 1-800-222-1222 for immediate assistance.

Chronic vitamin A toxicity

This can occur when someone takes high doses of vitamin A (typically exceeding 8,000 RAE) per day over a long period of time. This occurs most frequently when someone is consuming high vitamin A sources from animal-based products along with high dose vitamin A supplements.

Symptoms include:

• Severe headaches;
• Hair changes like sparse, coarse hair;
• Dry, rough, itchy skin and cracked lips;
• Weakness;
• Bone and joint pain;
• Enlarged liver or spleen;
• Increased hip fracture risk.

Pregnant women should avoid high doses of vitamin A, as it is teratogenic (meaning it can cause birth defects). Prenatal multivitamins are not considered high dose and are safe if consumed as a single serving.  Pregnant women should also generally avoid topical creams containing vitamin A (retinoids) as they can potentially harm a developing fetus.

Smokers or former smokers should avoid high dose vitamin A (including beta-carotene) supplements, as clinical trials show an increased risk of lung cancer.

Which Groups Might Benefit From a Vitamin A Supplement?

• People with cystic fibrosis. This condition makes it difficult to absorb fat, increasing the risk of vitamin A deficiency;
• People with gastrointestinal disorders such as Crohn’s Disease, celiac disease or ulcerative colitis, conditions which can affect nutrient absorption;
• Individuals with limited access to fresh foods, typically those in developing countries; however, it is possible in low-income communities in the US with poor access to food;
• Premature infants. Pre-term infants do not have adequate liver stores of vitamin A at birth, and their blood concentrations of retinol remain lowered through the first year of life;
• Children diagnosed with measles. High dose supplementation, under the supervision of a physician, may reduce severity and mortality in young children.

Can Vitamin A Interact With Medication?

• Hepatoxic medication. Combining high dose vitamin A supplements with other medications that can damage the liver, could increase the risk of liver conditions;
• Orlistat. This weight loss drug can interfere with the absorption of vitamin A, potentially reducing its effectiveness. It is recommended to take vitamin A at least 2 hours before or 2 hours after to minimize this interaction. Your health care provider might recommend a multivitamin supplement containing vitamin A and beta-carotene;
• Retinoids. You should avoid vitamin A supplement with retinoids, as it can lead to high levels of vitamin A in the blood;
• Warfarin.  Avoid high doses of vitamin A supplements, as it can increase the risk of bleeding.

Conclusions

Most Americans get sufficient vitamin A from dietary sources and do not need a supplement.  For healthy dietary patterns, see the Dietary Guidelines for Americans Current Dietary Guidelines | Dietary Guidelines for Americans and the US Department of Agriculture’s MyPlate.gov | U.S. Department of Agriculture.

Some people do require vitamin A supplementation. If supplementing vitamin A with a multivitamin or single dose nutrient supplement, be sure to check the label and avoid those with greater than 100% of the RDA to avoid potential toxicity. Vitamin A is an essential nutrient for health; however, it is important to avoid getting too much.

Resources

Song P, Adeloye D, Li S, Zhao D, Ye X, Pan Q, Qiu Y, Zhang R, Rudan I; Global Health Epidemiology Research Group (GHERG). The prevalence of vitamin A deficiency and its public health significance in children in low- and middle-income countries: A systematic review and modelling analysis. J Glob Health. 2023 Aug 11;13:04084. doi: 10.7189/jogh.13.04084. PMID: 37565390; PMCID: PMC10416138.

Converting Units of Measure for Folate, Niacin, and Vitamins A, D, and E on the Nutrition and Supplement Facts Labels

Vitamin A & Carotenoids, fact sheet for consumers.  June 15, 2022. NIH vitamina-Consumer.pdf

Vitamin A. April 17,2025.  Mayo Clinic Vitamin A - Mayo Clinic

Vitamin A toxicity: How much vitamin A is too much? April 21, 2023. Cleveland Clinic. Vitamin A Toxicity: How Much Vitamin A Is Too Much?

Olson JM, Ameer MA, Goyal A. Vitamin A Toxicity. [Updated 2023 Sep 2]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2025 Jan-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK532916/