Alpha-carotene is a carotenoid found in orange and dark green vegetables like carrots, sweet potatoes, and kale. The body converts a portion of it into vitamin A, which supports vision and immune function. It also acts as an antioxidant, helping shield cells from oxidative stress.
Most people get alpha-carotene from food. If you take a supplement, do so with a meal that contains fat to aid absorption. High intake from supplements has not been studied thoroughly, so getting it from whole foods is a safer choice.