text: Vitamin A is found in many foods. Vitamin A in food exists either as preformed retinol  an active form of vitamin A  found in animal liver, dairy and egg products, and some fortified foods, or as provitamin A carotenoids, which are plant pigments digested into vitamin A after consuming carotenoid-rich plant foods, typically in red, orange, or yellow colors. Carotenoid pigments may be masked by chlorophylls in dark green leaf vegetables, such as spinach. The relatively low bioavailability of plant-food carotenoids results partly from binding to proteins  chopping, homogenizing or cooking disrupts the plant proteins, increasing provitamin A carotenoid bioavailability.
  Vegetarian and vegan diets can provide sufficient vitamin A in the form of provitamin A carotenoids if the diet contains carrots, carrot juice, sweet potatoes, green leafy vegetables such as spinach and kale, and other carotenoid-rich foods. In the U.S., the average daily intake of β-carotene is in the range 2–7 mg.
  Some manufactured foods and dietary supplements are sources of vitamin A or beta-carotene.
  Despite the US setting an adult upper limit of 3,000 μg/day, some companies sell vitamin A (as retinal palmitate) as a dietary supplement with amounts of 7,500 μg/day. Two examples are WonderLabs and Pure Prescriptions.