Transferrin saturation is a medical term that refers to the amount of iron that is bound to transferrin in the bloodstream. Alternatively, it may also be known as serum iron or iron saturation. Some other potential synonyms for transferrin saturation include iron-binding capacity, total iron-binding capacity, and serum ferritin levels. These terms are all used in medical contexts to describe the amount and distribution of iron in the body, particularly in relation to various forms of anemia and other blood disorders. Depending on the specific diagnosis or test being performed, any of these terms may be used to describe the same general concept of iron levels in the blood.