What it is and where it comes from
Carotenes are the orange colour of carrots. For food they are made synthetically, or taken from algae, fungi, carrots or palm oil, all halal. Because carotene spoils in air and does not mix with water, makers often wrap it in tiny beads of gelatin, gum arabic or starch. When gelatin is used, its source matters.
Where you find it
Margarine, butter, soft drinks, juices, cheese, sweets, desserts and vitamin tablets.
What to look for on the label
The carrier is usually not on the label. A halal logo, a vegan label or a "suitable for vegetarians" label means no gelatin was used. Otherwise ask the maker.
This is a guide, not a fatwa. Recipes change, so check the label, look for halal certification, and ask your local imam where scholars differ.