Feosol caplet, also known as carbonyl iron, is one form of the mineral iron, according to Drugs.com. Carbonyl iron treats and prevents iron deficiencies and iron-deficiency anemia, and it is used as a dietary supplement.
Feosol caplet can decrease absorption of other pharmaceuticals, Drugs.com notes. Taking it can be dangerous for patients suffering from hemolytic anemia, hemosiderosis or hemochromatosis. Feosol caplet typically should not be taken by someone with a normal iron level. The drug should be kept away from children, because an accidental overdose can be deadly, according to Drugs.com.
Many bodily functions require iron, especially the transport of blood oxygen, the site notes.