Rat study: Iron deficiency does not effect testosterone or LH

Observational study: Anaemia associated with low testosterone in kidney patients
Causation not demonstrated. Indeed there is a good possibility causation works in the opposite direction as the men in the study with lower testosterone were less likely to be helped by erythropoietin-stimulating agents.

Observational study: Men taking exogenous testosterone had more hematocrit

22mg of Zinc reduces copper and iron satus in adolescents