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.