Alpha-carotene is a provitamin A carotenoid, similar to beta-carotene, which serves as a source of vitamin A for the body. Like beta-carotene, alpha-carotene is particularly abundant in orange vegetables and fruit 1. They differ in that alpha-carotene has only half of the vitamin A activity of beta-carotene.
Dietary carotenoids may either be absorbed through the intestines intact, or be cleaved to form vitamin A prior to absorption. There is no U.S. Food and Drug Administration (FDA) established Reference Daily Intake (RDI) for beta-carotene or other provitamin A carotenoids. However, dietary provitamin A carotenoids have vitamin A activity that can be expressed as retinol activity equivalents (RAEs) to be included as part of the RDI for vitamin A 2.