Foods containing vitamin B2: 1. animal offal, such as pig liver, chicken liver, goat liver and goose liver, which are rich in vitamin B2. 2. egg yolks, such as egg yolk, duck egg yolk and goose egg yolk, which are rich in vitamin B2. 3. dairy foods, such as milk, goat milk and horse milk, which are also rich in vitamin B2. These animal milks are also rich in vitamin B2.