Iron is important for immunity, but at certain times too much iron may be counter-productive. During an acute infection, iron is removed from the blood and stored in the liver. There is some evidence that this response prevents the growth of bacteria, since high levels of iron seem to stimulate the growth of bacteria. On the other hand, iron deficiency causes a fall in T-cell numbers, reducing immunity to infection. Unless there is clear iron deficiency anaemia, not AZT (zidovudine, Retrovir)-related anaemia, there is no good reason to supplement iron.

Good food sources of iron are meat (especially liver), poultry and fish.