It is the most abundant metal in the universe. By mass, it is the most common element on our planet, making up much of Earth’s core and some of its crust.
As minerals go, humans — indeed, most living things — can’t make it themselves and don’t need very much of it. But without even that little bit, we’d all be dead. That’s the irony of iron.
What Is Iron?
How hemoglobin works. (Credit: Designua/Shutterstock)
Iron is one of several essential nutrients (meaning we have to get it from the foods we eat) that humans need to maintain good health and the proper functioning of many of the body’s critical operations.
