Which of the following commonly causes metabolic alkalosis?

• A. Excessive bicarbonate intake
• B. Severe dehydration
• C. Hypocalcemia
• D. Acute kidney injury

Answer: (A)

Metabolic alkalosis is characterized by an increase in blood pH due to an elevation in bicarbonate levels or a loss of hydrogen ions. Excessive bicarbonate intake directly contributes to this condition, as it increases the bicarbonate concentration in the bloodstream. When bicarbonate levels rise, they can disrupt the acid-base balance, leading to a higher pH, which is the hallmark of alkalosis.

The other options, while they may influence the body's overall fluid and electrolyte balance, do not directly cause metabolic alkalosis in the same way. Severe dehydration can contribute to various electrolyte imbalances but is more commonly associated with metabolic acidosis or hypernatremia rather than creating an alkaline state. Hypocalcemia pertains specifically to low calcium levels and does not directly affect bicarbonate levels or pH in a way that would induce metabolic alkalosis. Acute kidney injury can lead to a variety of disturbances in acid-base balance, but it often results in metabolic acidosis due to the kidneys' inability to excrete acids, rather than an increase in bicarbonate levels.

Thus, the best option that directly leads to metabolic alkalosis is excessive bicarbonate intake.