What is the most common cause of hypomagnesemia?

What is the most common cause of hypomagnesemia?

• A. Alcoholism
• B. Hyperparathyroidism
• C. Hyperkalemia
• D. Hypophosphatemia

Answer: (B)

The main idea is that chronic alcohol use is the leading cause of low magnesium. In people with alcohol use disorder, magnesium intake is often poor and absorption can be impaired, and alcohol itself promotes urinary magnesium loss. This combination—decreased intake plus renal wasting—makes hypomagnesemia very common in these patients. Hyperparathyroidism mainly affects calcium and phosphate balance and isn’t a primary driver of low magnesium; while severe magnesium deficiency can interfere with PTH secretion, it isn’t the typical cause. Hyperkalemia isn’t a primary cause of magnesium loss, and hypophosphatemia reflects phosphate abnormalities rather than being the usual trigger for low magnesium, though electrolyte disturbances can coexist.

The main idea is that chronic alcohol use is the leading cause of low magnesium. In people with alcohol use disorder, magnesium intake is often poor and absorption can be impaired, and alcohol itself promotes urinary magnesium loss. This combination—decreased intake plus renal wasting—makes hypomagnesemia very common in these patients.

Hyperparathyroidism mainly affects calcium and phosphate balance and isn’t a primary driver of low magnesium; while severe magnesium deficiency can interfere with PTH secretion, it isn’t the typical cause. Hyperkalemia isn’t a primary cause of magnesium loss, and hypophosphatemia reflects phosphate abnormalities rather than being the usual trigger for low magnesium, though electrolyte disturbances can coexist.