What is the primary function of albumin in the body?

Albumin plays a crucial role in maintaining oncotic pressure, which is essential for regulating the movement of fluid between the blood vessels and surrounding tissues. Oncotic pressure is primarily influenced by the concentration of proteins, particularly albumin, in the blood plasma. When albumin levels are adequate, it helps to prevent excess fluid from leaking out of the blood vessels and into the interstitial spaces, which can lead to edema.

In addition to its role in oncotic pressure, albumin also has other functions, such as transporting various substances including hormones, vitamins, and drugs in the bloodstream. However, its primary and most significant function is the maintenance of oncotic pressure, making it vital for fluid balance and overall physiological stability in the body. Other options, like catalyzing biochemical reactions and immune responses, are not functions associated with albumin but rather with enzymes and immune proteins, respectively.