Why is there iron in my cereal? Is there iron in other food? -Phillip, 11, Pullman, WA

Dear Phillip,

Iron is found in buildings and skyscrapers. It makes up most of the Earth’s core. It’s even found in the Sun and stars. And yes, it’s also in a bowl of cereal.

In nature, we might find iron in a black and steely mineral form buried deep in the earth. But right in our bodies, we also find iron in blood.

That’s what I found out from my friend Brennan Smith when we set out to investigate why there’s iron in cereal and other foods.

Smith is a professor of food science who teaches students at Washington State University and the University of Idaho. He explained that iron is in cereal and other foods for our nutrition. I wondered exactly what it does for us.

Smith explained that in your blood you have something called hemoglobin, which gives your blood its red color. Hemoglobin also helps carry oxygen through your body. But it can’t do this without the help of iron.

Iron helps bind the oxygen you breathe to the hemoglobin. The hemoglobin holds onto the oxygen and carries it through your body to help you stay strong.

Screen Shot 2016-04-04 at 9.05.13 AM“That’s one of the most important reasons why we have iron,” Smith said.

Without iron, you might start feeling weak and tired because your body isn’t getting enough oxygen. But eating foods with the right amount of iron helps you grow, think, and play.

My friend Jen Hey, another expert in nutrition here at WSU, said good sources of iron are eggs, beans, some kinds of shellfish, and meat. Mmm, I was starting to get hungry. There’s also iron in tofu, dried fruit, and dark, leafy green vegetables.

The plants farmers grow to make cereal grains also need iron, too. These plants use iron to help carry oxygen, just like in people. And without iron, they wouldn’t be able to make their green colors.

A lot of plants and animals naturally have a lot of iron. Sometimes there are foods that are fortified, and iron is added to give it a boost.

It depends on what kind of cereal you are eating, but usually there is a small amount of iron combined with other ingredients. Just read the label and you’ll find out about things like zinc, calcium, and vitamins.

From the stars in outer space to plants in a field to the cereal in your bowl, iron is an important element in our universe. Iron is a kind of metal. Metals can also be magnetic. Iron is magnetic, too. That’s why you can grind up some cereals and get the iron out with a magnet.

There might even be some iron in the metal spoon you use to eat your cereal in the morning.

If you like food and science, perhaps you might want to be a food scientist one day, Phillip. In fact, with a question like this one, you are well on your way.

“Keep asking lots of questions,” Smith said. “Always be asking questions.”

Sincerely,
Dr. Universe