Hypercalcemia due to milk alkali syndrome: An emerging cause of hypercalcemia: A case report and review of literature

Introduction: Hypercalcemia is relatively common in clinical practice. Primary hyperparathyroidism and malignancy accounts for more than 90 percent of all cases of hypercalcemia. Milk alkali syndrome which is hypercalcemia classically caused by ingestion of large amount of calcium and absorbable alkali which was once virtually disappeared as a cause of hypercalcemia has emerged as a third leading cause of hypercalcemia. We present a case of hypercalcemia secondary to ingestion of calcium carbonate tablets resulting in milk alkali syndrome.Case presentation: Patient is a 45-year-old female with history of gastroesophageal reflux disease came to the emergency department with complaints of dizziness, constipation, fatigue and confusion for 3 weeks. She was hypotensive to 83/53 mmHg at arrival. Significant laboratory results were - Potassium of 2.2 mmol/L (3.5-5.1 mmol/L), chloride 73 mmol/L (98-107 mmol/L), Bicarbonate 50 mmol/L (22-29 mmol/L), Blood urea 22 mg/dl (9.8-20.1 mg/dl), Cr 1.4 mg/dl (0.5-1.0 mg/dl), total calcium of 16.6 mg/dl (9-11 mg/dl), ionized calcium 2.02 mmol/L (1.15-1.33 mmol/L), PTH was low to 8.9 pg/ml (10-65 pg/ml). Arterial blood gas showed metabolic alkalosis. Extensive evaluation to find the cause of hypercalcemia was negative. Detailed history after initial stabilization, revealed that she had been taking 10 tablets of calcium carbonate tablets per day and 1 glass of milk daily for reflux symptoms for the last eight weeks. Based on the history and after ruling out all the other serious causes, diagnosis of milk alkali syndrome was made and patient was discharged with proton pump inhibitor with advice to avoid calcium carbonate. Her hypercalcemia responded well to fluid resuscitation.Conclusions: Milk alkali syndrome once a rare cause of hypercalcemia has emerged as a third leading cause of hypercalcemia in completely different scenario. It is important to evaluate the patient with proper history including the use of over the counter calcium supplements to determine the etiology of hypercalcemia. Our case highlights the importance of proper history taking in the evaluation of hypercalcemia and that not all the cause of severe hypercalcemia is secondary to malignancy.