Beta-carotene

Also known as betacarotene, provitamin A, beta caroteen.

Last reviewed October 9, 2026 · Jump to references

What is Beta-carotene?

In plain words

Beta-carotene is an orange-yellow pigment found in carrots, sweet potatoes, and leafy greens. The body converts some of it into vitamin A, which helps maintain vision and immune function. Researchers study its role in nutrition, eye health, and disease prevention. High-dose beta-carotene supplements have increased lung cancer risk in trials involving smokers and people exposed to asbestos.

Technical definition

Beta-carotene is a plant-derived, fat-soluble carotenoid (C40H56) with a conjugated polyene chain and two beta-ionone rings; it functions as a provitamin A rather than a direct receptor agonist. Beta-carotene oxygenase 1 cleaves it to retinal, which supports vision and can be converted to retinol or retinoic acid, a regulator of gene expression through nuclear retinoic acid receptors. It is used in foods and dietary supplements; in the United States, supplements are not FDA-approved for safety and effectiveness before marketing.

Educational information only. This page does not provide medical advice or determine whether a supplement is appropriate for you. Review supplements with a qualified healthcare professional, especially if you take medication, are pregnant, have surgery scheduled, or have a chronic medical condition.

Evidence by use

Each use is rated on its own. There is no single overall effectiveness score.