Iron
Human bodies need iron to help oxygen get to our muscles, because it is at the heart of some essential macromolecules such as hemoglobin. Many cereals have some added iron (the element metal iron). It is added to cereal in the form of tiny metal filings. It is even possible to see the slivers sometimes by taking an extremely strong magnet and putting it into the box. The magnet will attract these pieces of iron. Eating these small metal shavings are not harmful to our body.