Vitamin B2, more commonly recognised as riboflavin, helps the body to be healthy in general, but is particularly good at keeping the eyes, skin and nervous system healthy, as well as releasing energy from food. Good sources of riboflavin include milk, eggs, rice and fortified breakfast cereals.
You should be able to get your recommended daily dose of riboflavin by maintaining a healthy, balanced diet. If you take supplements, do not take too much as this might be harmful. That said, taking 40mg or less a day of riboflavin supplements is unlikely to cause any harm.