Milk fluoridation is practiced by the Borrow Foundation in some parts of Bulgaria, Chile, Peru, Russia, Macedonia, Thailand and the UK. Depending on location, the fluoride is added to milk, to powdered milk, or to yogurt. For example, milk powder fluoridation is used in rural Chilean areas where water fluoridation is not technically feasible. These programs are aimed at children, and have neither targeted nor been evaluated for adults. A systematic review found low-quality evidence to support the practice, but also concluded that further studies were needed.