Edema in protein-energy malnutrition is due to insufficient synthesis of which protein?

• A. Hemoglobin
• B. Collagen
• C. Albumin
• D. Fibrinogen

Answer: (C)

The key idea is how albumin helps keep fluid inside blood vessels. Albumin is the most abundant protein made by the liver and creates the plasma’s oncotic (colloid osmotic) pressure that pulls fluid back into the circulation. In protein-energy malnutrition, not enough dietary protein leads to reduced synthesis of albumin, causing hypoalbuminemia. With lower albumin levels, capillary oncotic pressure falls, so more fluid filters out into the interstitial space and less is reabsorbed into the blood, producing edema. The other proteins serve different roles—hemoglobin for oxygen transport, collagen for structural tissue, and fibrinogen for clotting—not primarily involved in maintaining intravascular fluid balance.