 Pro-vitamin A carotenoids in plants are a major and safe vitamin A source for a vast population in the world. Even though, ß-carotene ß-C in vegetables has been considered as a safe vitamin A source, it is essential to determine the efficiency of provitamin A carotenoids in plant conversion to vitamin A. However, the bioavailability of vitamin A and carotenoids from food matrices has not been well studied due to the unavailability of isotopically labeled foods that can be fed to humans. 