Which of the following tests provides information regarding liver function aside from GGT?

The selection of ferritin as the test that provides information regarding liver function is based on its role in reflecting the state of iron stores within the body, which is closely related to liver health. While ferritin itself is primarily a measure of iron storage, it can be indicative of liver function because the liver plays a key role in iron metabolism and storage. Elevated ferritin levels can occur in cases of liver inflammation or disease, making it relevant when assessing liver function.

In contrast, the other tests mentioned have different primary functions. BUN (blood urea nitrogen) primarily assesses kidney function, while folate is a vitamin important for DNA synthesis and cell division, not directly linked to liver assessment. Immunoglobulin tests evaluate immune response rather than directly indicating liver function. Thus, ferritin stands out as a crucial marker when considering liver function alongside other tests.