This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Fluids and Electrolyte Imbalance, Subject name: Medicine
Not a cause of Hypomagnesemia: 
Select and explain. 
A. Gitelman syndrome, B. Re-feeding syndrome, C. Hyperaldosteronism, D. Rhabdomyolysis
D: Rhabdomyolysis
Answer: D: Rhabdomyolysis 
Explanation: * Gitelman is a defect of DCT where TRPM6 receptor for magnesium reabsorption is present and is defective leading to Hypomagenesemia * In Re-feeding syndrome seen with starvation, provision of nutrition in form of substrates will lead to cellular consumption leading to rapid shift of magnesium from extracellular fluid to intracellular compaments. * Hyperaldosteronism will lead to expansion of plasma volume and resultant fall of magnesium. * In Rhabdomyolysis cell destruction will lead to Hypermagnesemia.