Iron-CItem Description Highly absorbable iron formula with vitamin C to enhance intestinal absorption; supports red blood cell function and energy production* Iron is an important component of hemoglobin, a protein in red blood cells that delivers oxygen to tissues throughout the body. It is also a part of myoglobin, a protein that helps muscle cells store oxygen and ferritin, the body's main iron storage protein found in the intestines, liver, and spleen.