Volume depletion involves loss of body water and electrolytes. Which component is lost?

• A. Electrolytes
• B. Proteins
• C. Sugars
• D. Lipids

Answer: (A)

Volume depletion comes from loss of isotonic fluid from the extracellular space, so both water and dissolved electrolytes are lost. The key component that goes with that fluid loss is electrolytes, such as sodium and chloride, which is why replacing electrolytes is essential. Proteins, sugars, and lipids aren’t the primary components lost in this scenario; they remain in the vascular and cellular compartments unless a separate condition causes their loss. So the component lost in volume depletion is electrolytes.