Which laboratory marker is used to estimate liver function?

The laboratory marker that is primarily used to estimate liver function is albumin. Albumin is a protein synthesized in the liver, and its levels in the blood are indicative of the liver's synthetic capability. A decrease in albumin levels can suggest liver dysfunction or disease, as the liver may not be producing enough of this crucial protein due to conditions such as cirrhosis or acute liver failure.

While alkaline phosphatase and bilirubin are also related to liver conditions, they primarily reflect biliary function and liver obstruction rather than the overall liver synthesis ability. Creatinine is mainly a marker for kidney function and does not provide direct insights into liver performance. Thus, albumin stands out as the key indicator for assessing liver function among the options listed.