Which deficiency is characterized by mental status changes, convulsions, and cerebral edema?

The deficiency characterized by mental status changes, convulsions, and cerebral edema is sodium deficiency, often referred to as hyponatremia. Sodium is a crucial electrolyte in the body that helps maintain osmotic balance and is essential for normal nerve and muscle function. When sodium levels drop significantly, it can lead to serious neurological symptoms due to the resulting imbalance in fluid distribution across cellular membranes.

In the case of hyponatremia, the low sodium concentration in the extracellular fluid causes water to shift into cells, leading to cellular swelling and, in particular, edema in the brain. This cerebral edema can manifest as confusion, altered levels of consciousness, convulsions, and in severe cases, coma or death. Thus, the combination of mental status changes, convulsions, and cerebral edema aligns with the clinical features of sodium deficiency.

The other electrolytes listed have different effects on the body. For example, calcium deficiency is more typically associated with muscle spasms or tetany, while potassium deficiency relates to muscle weakness and cardiac arrhythmias. Magnesium deficiency may lead to neuromuscular excitability and can cause similar convulsions but would not primarily be associated with the classic signs of cerebral edema seen in hyponatremia.