Carotenoids are organic pigments produced by plants, algae, and some microorganisms, responsible for the vibrant yellow, orange, and red colors seen in many fruits and vegetables. They are tetraterpenoids, meaning they have a complex structure of 40 carbon atoms, and are broadly classified into two groups: xanthophylls (oxygen-containing, e.g., lutein, astaxanthin) and carotenes (hydrocarbons, e.g., beta-carotene, lycopene). In humans, carotenoids act as potent antioxidants, protecting cells from damage caused by free radicals and oxidative stress. This protective action is linked to their potential role in reducing the risk of various chronic diseases and supporting overall cellular health. They are fat-soluble compounds, meaning they are best absorbed when consumed with dietary fats. Crucially, some carotenoids, known as provitamin A carotenoids (e.g., beta-carotene, alpha-carotene, beta-cryptoxanthin), can be converted into Vitamin A within the body. Vitamin A is essential for healthy vision, immune function, cell growth, and reproduction. Other carotenoids, such as lutein and zeaxanthin, are important for eye health, accumulating in the retina to filter harmful blue light and protect against age-related macular degeneration.