Carotenoids are the yellow-red pigments that give carrots their vibrant, deep orange color. There are over 600 different carotenoids, but only 3—beta-carotene (β-carotene), beta-cryptoxanthin (β-cryptoxanthin), and alpha-carotene (α-carotene)—can be converted to vitamin A. These three provide approximately 25 to 35 percent of the dietary vitamin A consumed by adults in the United States, with the majority of it coming from beta-carotene.
It is easy to consume beta-carotene in the diet. A daily recommendation for beta-carotene hasn't been established, but the Institute of Medicine recommends consuming 3 to 6 milligrams of beta-carotene from food daily. You can obtain this easily by eating five or more servings of deep orange and dark green fruits and vegetables daily, such as cantaloupe, mangoes, spinach and broccoli.