Infection and iron metabolism.

An important component of nonspecific defense of vertebrates against microbial invasion is that of nutritional immunity. Hosts attempt to withhold growth-essential iron from invading bacteria, fungi, and protozoa. Clinical conditions in which hosts are stressed by excess quantities of iron in specific fluids, tissues, or cells result in enhanced susceptibility to infection. Methods for strengthening nutritional immunity are known in theory; research is needed to determine if these would be useful in clinical practice.