Iron overload occurs in all except
Thalassemia
Myelodysplastic syndrome
Polycythemia vera
Sideroblastic anemia
Ref Harrison 19 th ed pg 626, 673 Increased erythropoietin leads to increased haematopoasis and an increased demand for iron producing a state of iron deficiency. Polycythemia vera being a state of increased erythropoietin is a cause of iron deficiency rather than iron overload.
Haematology