A nutrition researcher evenly divides a large group of 3-week-old healthy laboratory mice into two groups and keeps the animals in separate rooms. He adds 30 mg of the mineral iron to the daily diet of one group of the mice. The other group of mice receives the same diet as the first group, but their diet does not contain additional iron. After ten weeks, the scientist takes blood samples from each mouse. According to his findings, the mice that obtained the iron supplement developed abnormal levels of certain enzymes in their red blood cells. Based on this information and your knowledge of scientific research, what would you tell him?