The entire family of carotenes are found naturally in many vegetables and fruits. Specifically, beta carotene is found in dark orange or green vegetables and fruits. The difference between a dark orange carrot and a pale one is its carotene content. Beta carotene and other carotenoid supplements are an appealing and convenient way to make up the difference. Unfortunately, most diets are lacking in these important nutrients. Beta and alpha carotene are precursors to vitamin A and act as antioxidant nutrients. They are the only carotenoids converted to appreciable amounts of vitamin A.
However, the body only converts these carotenoids into vitamin A as needed. Beta and alpha carotene are important for the immune system and provide resistance to infection.They are also necessary for the development and maintenance of healthy epithelial tissue and mucous membranes such as, the lining of the lungs, bronchi, and other respiratory tissues. Epithelial tissue forms a barrier against bacteria and other foreign substances and aids directly in the prevention of infection and disease.