What is the primary function of albumin in the body?

Albumin plays a crucial role in maintaining oncotic pressure, which is the osmotic pressure exerted by proteins in the blood plasma. This pressure is essential for regulating the balance of fluids between the blood vessels and surrounding tissues. By retaining fluid within the vascular compartment, albumin helps prevent edema and ensures adequate circulation and nutrient delivery to tissues.

The protein is synthesized in the liver and constitutes a significant portion of the total protein content in plasma, providing a stable environment for blood volume and pressure. A decrease in albumin levels can lead to a decline in oncotic pressure, resulting in fluid leakage into interstitial spaces, which contributes to conditions like peripheral edema and ascites.

Other options reflect different physiological processes that are not directly related to the primary function of albumin. For instance, transporting oxygen in the blood is primarily the role of hemoglobin in red blood cells, while digesting fats is performed by enzymes produced in the pancreas and bile acids from the liver. Controlling blood sugar levels involves hormones like insulin and glucagon, rather than albumin. Therefore, within the context of its primary biological role, maintaining oncotic pressure stands out as the correct function of albumin.