What foods contain riboflavin?

Pasta and most breads made from refined flours are enriched with riboflavin because riboflavin is one of the nutrients lost in processing.
Riboflavin is also known as vitamin B2

Milk, cheese, leafy green vegetables, liver, kidneys, legumes, tomatoes, yeast, mushrooms, and almonds are all good sources of riboflavin.

It is sometimes used to fortify some foods like baby food, breakfast cereals and energy drinks. In the some countries like the USA they add it to white flour to make up for what was lost in the milling process