Which laboratory result is typically high in cases of iron deficiency?

In cases of iron deficiency, total iron-binding capacity (TIBC) is typically elevated. This occurs because the body senses low levels of iron and compensates by increasing the production of transferrin, the protein responsible for transporting iron in the blood. As iron stores deplete, the liver produces more transferrin to maximize the amount of iron that can be absorbed from the diet and utilized by the body.

On the other hand, serum iron levels will be low due to the deficiency, and ferritin, which reflects stored iron in the body, will also be reduced. Mean corpuscular hemoglobin concentration (MCHC) might show normal or even decreased levels as well, depending on the severity and duration of the deficiency, as it measures the average concentration of hemoglobin in a given volume of red blood cells.

Thus, elevated TIBC is a key laboratory finding that supports the diagnosis of iron deficiency, indicating the body's attempt to increase iron availability in response to low iron levels.