Iron is one of the most abundant metals in the human body and is critical for normal physiological functions. It is a crucial part of hemoglobin, a protein found in red blood cells that is responsible for delivering oxygen to all the body’s cells. Iron also supports muscle metabolism and healthy connective tissue, and is necessary for physical growth, neurological development, cellular functioning and the synthesis of some hormones. D.I.I. selectively focuses on the excess iron that has been excreted to the surface of your skin because your body does not need it, while avoiding the ferritin circulating in your bloodstream, which your body may need to perform critical functions. You should speak with a doctor or dietitian before modifying your diet.