Refeeding syndrome MOA involves which primary event?

• A. Sudden drop in phosphorus due to rapid glucose uptake and glycolysis
• B. Hyperkalemia due to insulin surge
• C. Hyponatremia due to water retention
• D. Hypocalcemia due to phosphate shifts

Answer: (A)

When feeding a severely malnourished patient again, the body’s insulin response to carbohydrates is the key driver. This surge pushes glucose into cells to restart metabolism and, in the process, drives phosphate into cells to support ATP production and glycolysis. The result is a rapid drop in serum phosphate, or hypophosphatemia, which is the main initiating event in refeeding syndrome. This phosphate depletion disrupts cellular energy balance and can lead to serious complications like cardiac and respiratory failure, weakness, and arrhythmias. The other options describe electrolyte changes that can occur with insulin or fluid shifts, but they are not the primary initiating event driving refeeding syndrome.