(Fe, Fe2+, Fe3+, lat. Ferrum)

Although the iron content of the earth's crust is relatively high, in the human body is only 3-4 grams of it. About two-thirds are in the blood.

Therapeutic use of iron dates back to thousands of years ago. Egyptians transcribed iron supplements for treatment of hair loss, while the Greeks recommending iron in addition to wine because it increases the potency of men.