What is a common cause of hypophosphatemia?

Hypophosphatemia, which is characterized by low levels of phosphate in the blood, can arise from several conditions, but one of the most notable causes is refeeding syndrome or excessive antacid use.

Refeeding syndrome typically occurs when feeding is restarted in individuals who have been malnourished or have experienced prolonged fasting. When carbohydrates are reintroduced, the body's insulin secretion increases, leading to a shift of phosphate from the extracellular fluid into cells, which can result in hypophosphatemia. This is particularly critical in cases where phosphorus levels were already low due to malnutrition.

Similarly, excessive use of antacids, especially those that contain aluminum or magnesium, can bind to phosphorus and lead to decreased absorption in the gastrointestinal tract, thereby contributing to hypophosphatemia.

In contrast, while excessive hydration, chronic dehydration, and a high protein diet can have various effects on electrolyte levels, they are not common or direct causes of hypophosphatemia like refeeding syndrome and excessive antacid use are.