What is albumin?

Albumin is a protein that plays several critical roles in the body, including helping to maintain oncotic pressure, transporting various substances in the blood, and regulating blood volume. While it does have some involvement in the immune system, its primary function is not to fight infections directly as antibodies do. However, being a protein that circulates in the blood, albumin contributes to the overall health of the immune system by ensuring proper nutrient transport and fluid balance.

In the context of blood, albumin is the most abundant plasma protein and is essential for keeping fluids from leaking out of the blood vessels—this is crucial for maintaining overall homeostasis. Its ability to bind and transport hormones, vitamins, and drugs further underscores its importance in physiological processes. Thus, describing albumin as a protein aligns with its defined role in biological systems.