Cheerful Little Os Our tasty and crunchy little Os are beaming with goodness†! High in fibre from oats, wheat and barley with 7 vitamins, calcium and iron, and no artificial colours and flavours. With each bowl of Cheerios, your family can enjoy a nutritious† breakfast and a delicious start to the day! †Cheerios are a source of iron, vitamins B6 and B9 which contribute to normal function of the immune system.