What is one of the main functions of proteins in the body?

Proteins play a crucial role in maintaining fluid and electrolyte balance because they help regulate the movement of water in and out of cells and between different compartments within the body. Proteins, especially albumin, act as colloids that attract water, helping to maintain osmotic pressure in the bloodstream. This osmotic pressure is essential for proper hydration of cells and tissues, allowing them to function effectively.

While proteins can be involved in the absorption of some vitamins, particularly fat-soluble ones through the formation of chylomicrons, their primary function is not solely focused on vitamin absorption. Similarly, proteins do participate in energy metabolism, but they are not the body's primary energy source; that role is mainly filled by carbohydrates and fats. Therefore, the optimal understanding of proteins highlights their pivotal role in fluid and electrolyte balance, making this function a significant aspect of their biological importance.