During refeeding, which electrolytes require close monitoring?

• A. Magnesium and calcium
• B. Phosphate and potassium
• C. Sodium and chloride
• D. Iron and zinc

Answer: (B)

Refeeding syndrome happens when nutrition is restarted after starvation, and insulin drives phosphate, potassium, and magnesium into cells. This can drop serum phosphate quickly (hypophosphatemia), which is a hallmark and can lead to serious problems like respiratory or cardiac failure; potassium losses are also common and can trigger arrhythmias. Because of these risks, electrolytes that require close monitoring are phosphate and potassium. Magnesium is also important to watch, but the combination of phosphate and potassium best reflects the two most urgent early disturbances. Sodium and chloride relate more to fluid balance, while iron and zinc are trace elements not acutely affected in the same initial way.