2026 ASCP Clinical Chemistry Complete Practice Test

Increased levels of both serum iron and % saturation are indicative of iron overload conditions. When there is an excess of iron in the body, either due to high dietary intake, excessive supplementation, or genetic conditions like hemochromatosis, serum iron levels rise. This excess iron also increases the percentage saturation of transferrin, the main iron transport protein in the blood, as more iron binds to this protein.

In situations of iron overload, the body experiences a buildup of iron beyond normal storage levels, leading to elevated serum iron and a correspondingly higher percentage of transferrin that is saturated with this iron. This is in direct contrast to conditions such as vitamin D deficiency, chronic infections, or malignancies, which do not typically increase serum iron or % saturation in the same manner and are associated with different metabolic responses in the body. Therefore, iron overload is the condition that specifically leads to the described changes in iron parameters.