Which of the following can cause hypophosphatemia?

• A. Dehydration
• B. Excessive antacid use
• C. Chronic hypertension
• D. High carbohydrate diet

Answer: (B)

Hypophosphatemia, which is a condition characterized by low levels of phosphate in the blood, can result from several factors. Among the options provided, excessive antacid use is particularly relevant because many antacids contain aluminum, which can bind to phosphate in the gastrointestinal tract, leading to decreased absorption. This form of phosphate sequestration contributes significantly to lower serum phosphate levels. Furthermore, certain antacids may increase urinary excretion of phosphate, further compounding the risk of developing hypophosphatemia.

Dehydration does not specifically lead to decreased phosphate levels as the body's fluid balance is more closely related to the concentration of electrolytes without significantly affecting phosphate absorption or excretion. Chronic hypertension does not directly impact phosphate levels, and while a high carbohydrate diet might transiently affect phosphate metabolism by increasing insulin levels (which can drive phosphate into cells), it is not a common cause of clinically significant hypophosphatemia in the same manner as excessive antacid use.