What is vitamin A labeled as?

January 9, 2026 •

3 min read

According to the National Institutes of Health, vitamin A is a group of fat-soluble retinoids, and its labeling has evolved from International Units (IU) to Retinol Activity Equivalents (RAE) to more accurately reflect the vitamin's bioavailability from different sources. This change helps consumers make more informed dietary choices.

Quick Summary

Vitamin A is labeled using Retinol Activity Equivalents (RAE) instead of the older International Units (IU) on nutritional products and supplements. This change improves accuracy by reflecting the bioavailability difference between preformed vitamin A (retinoids) and provitamin A (carotenoids).

Key Points

Measurement Change: Vitamin A is now measured in Retinol Activity Equivalents (RAE) on labels, replacing the older International Units (IU).
Different Forms: Vitamin A can be labeled as preformed (retinoids like retinol, retinyl acetate) from animal sources or provitamin (carotenoids like beta-carotene) from plant sources.
Bioavailability Matters: The shift to RAE standardizes how the body uses different forms, as preformed vitamin A is more readily absorbed than provitamin A.
Reading the Label: Look for "mcg RAE" and check for additional source information, such as "as Beta-carotene".
Toxicity Differences: Preformed vitamin A can be toxic in excessive doses, especially from supplements, while provitamin A from food does not pose a toxicity risk.

Understanding the New Vitamin A Label: RAE vs. IU

Navigating a nutrition facts panel or supplement label can be confusing, especially with changes to how nutrients are measured and listed. The labeling of vitamin A underwent a significant update to provide more precise information about its bioavailability. Historically, vitamin A was measured in International Units (IU), but the modern standard, Retinol Activity Equivalents (RAE), offers a more accurate representation of how the body utilizes different forms of this essential nutrient. This article will delve into what vitamin A is labeled as, the different forms it can take, and how to interpret this information for your diet.

The Shift to Retinol Activity Equivalents (RAE)

The move from IU to RAE on nutrition labels was mandated by the U.S. Food and Drug Administration (FDA) and took effect for most companies in 2020 and 2021. The primary reason for the change was that IU does not account for the differing bioactivities of various vitamin A sources. For example, preformed vitamin A from animal sources is more readily absorbed by the body than provitamin A carotenoids from plants. RAE standardizes these differences, allowing for a more accurate comparison of vitamin A content across products and dietary sources.

Preformed Vitamin A (Retinoids)

Retinol: The active form of vitamin A, found in animal-based products.
Retinyl Esters (e.g., retinyl acetate, retinyl palmitate): The storage form of vitamin A found in animal sources like liver, fish oil, and fortified dairy. These are converted to retinol in the body.

Provitamin A (Carotenoids)

Beta-carotene: The most common provitamin A carotenoid, found in colorful fruits and vegetables. The body converts this into retinol.
Alpha-carotene and Beta-cryptoxanthin: Other provitamin A carotenoids that are also converted to retinol.

Reading the Vitamin A Content on a Label

To read the vitamin A content on a modern nutrition facts panel, you should look for the measurement in "mcg RAE." Below that, the label may also specify the sources of vitamin A, such as "(as Beta-carotene)" or "(as Retinyl Palmitate)." This information is crucial for understanding where your vitamin A is coming from and its relative bioavailability.

For example, the conversion factors to RAE highlight the disparity in bioavailability:

1 mcg RAE = 1 mcg retinol
1 mcg RAE = 2 mcg supplemental beta-carotene
1 mcg RAE = 12 mcg dietary beta-carotene
1 mcg RAE = 24 mcg dietary alpha-carotene or beta-cryptoxanthin

This means that 1 mcg of preformed retinol is significantly more potent than 1 mcg of beta-carotene from food.

Comparing Vitamin A Sources

To illustrate the difference in bioavailability and labeling, consider the following comparison table:


Feature	Preformed Vitamin A (Retinoids)	Provitamin A (Carotenoids)
Source	Animal products (liver, fish oil, dairy)	Plant-based foods (carrots, sweet potatoes, spinach)
Chemical Forms	Retinol, Retinyl Acetate, Retinyl Palmitate	Beta-carotene, Alpha-carotene, Beta-cryptoxanthin
Body Conversion	No conversion needed; immediately active	Converted by the body into retinol
Bioavailability	High	Lower, varies by source
Measurement (RAE)	1 mcg RAE = 1 mcg Retinol	1 mcg RAE = 12 mcg dietary Beta-carotene
Risk of Toxicity	Higher, can accumulate in the body	Very low, not toxic even in large doses

The Role of Vitamin A in the Body

Vitamin A is a vital fat-soluble vitamin with multiple functions that support overall health.

Vision: Known as retinol because it produces the pigments in the retina of the eye, vitamin A is crucial for good eyesight, especially in low light conditions. A deficiency can lead to night blindness.
Immune Function: Vitamin A plays a significant role in maintaining a healthy immune system, supporting the function of immune cells.
Cell Growth and Differentiation: It is involved in the growth and differentiation of various cells, helping to maintain the health of skin and mucous membranes.
Reproduction: Vitamin A is essential for proper reproductive function and fetal development.
Antioxidant Properties: Carotenoids, the provitamin A forms, also function as antioxidants, protecting cells from damage caused by free radicals.

Conclusion: Making Sense of Your Labels

In conclusion, when you see a nutrition label, knowing what vitamin A is labeled as is key to making a truly informed decision. The use of Retinol Activity Equivalents (RAE) provides a more accurate measure of the vitamin's potency compared to the outdated International Units (IU). By identifying whether the vitamin A is derived from preformed (animal-based) sources like retinyl palmitate or provitamin (plant-based) sources like beta-carotene, you can better understand its bioavailability and how it contributes to your daily intake. For further reading and information on dietary supplements, you can visit the NIH's Office of Dietary Supplements website at https://ods.od.nih.gov/factsheets/VitaminA-Consumer/.

Frequently Asked Questions

The labeling changed from IU to RAE because International Units (IU) did not accurately reflect the different bioactivities and absorption rates of the various forms of vitamin A. Retinol Activity Equivalents (RAE) provide a more standardized and accurate measure.

Preformed vitamin A, such as retinol and retinyl esters, is found in animal products and is readily used by the body. Provitamin A, like beta-carotene found in plants, must be converted into retinol by the body, making it less bioavailable.

Yes, it is possible to consume too much preformed vitamin A, particularly from supplements, which can lead to toxicity (hypervitaminosis A). Excessive intake of provitamin A from food sources is generally not considered toxic, though it may cause a harmless yellow-orange tint to the skin.

On a current food label, you will find vitamin A listed on the 'Supplement Facts' or 'Nutrition Facts' panel. It will be measured in micrograms (mcg) of Retinol Activity Equivalents (RAE).

No, not all carotenoids can be converted into vitamin A. While beta-carotene is the most common provitamin A, others like alpha-carotene and beta-cryptoxanthin can also be converted. Other carotenoids like lycopene do not have retinoid activity.

Converting IU to mcg RAE depends on the source of the vitamin A. For example, 1 IU of supplemental beta-carotene equals 0.3 mcg RAE, while 1 IU of dietary beta-carotene equals just 0.05 mcg RAE. The conversion rate is different for each form.

The FDA regulations require the use of mcg RAE on both Supplement Facts and Nutrition Facts panels. However, a food label may specify the type of provitamin A, like beta-carotene, in parentheses.