What is the most common cause of hypomagnesemia?

Hypomagnesemia, or low levels of magnesium in the blood, is most commonly associated with chronic alcoholism. This condition is frequently seen in individuals with substance use disorders due to several reasons. Alcohol can interfere with the absorption of magnesium from the gastrointestinal tract and can also increase renal excretion of magnesium, leading to a significant deficiency over time. Additionally, alcohol-related dietary deficiencies and malnutrition contribute to reduced magnesium intake, further exacerbating the risk of developing hypomagnesemia.

In contrast, excessive physical activity isn't typically a direct cause of hypomagnesemia, as while intense exercise can lead to electrolyte imbalances, it usually does not singularly result in low magnesium levels unless combined with inadequate dietary intake. High dietary intake of magnesium is unlikely to cause hypomagnesemia; in fact, it generally supports maintaining adequate levels. Acute kidney failure can affect magnesium levels, but it is more commonly associated with hypermagnesemia due to decreased excretion rather than contributing to low magnesium levels. Therefore, chronic alcoholism stands out as the primary contributor to hypomagnesemia.