Endocrine Abstracts

Introduction: Hypoparathyroidism treatment is aimed to achieve a serum calcium at the lower limit of normal providing symptom resolution and preventing complications such as urolithiasis and renal impairment. Milk-alkali syndrome (MAS) incidence has been gradually rising associated with the increase of calcium carbonate and vitamin D supplementation. The classic triad is characterized by metabolic alkalosis, hypercalcemia and renal failure.

Case report: A 34-year-old male with DiGeorge syndrome was referred to the Endocrinology clinic due to primary hypoparathyroidism. Previous personal history was relevant for Evans syndrome under Eltrombopag treatment, epilepsy and schizophrenia. He was treated with a calcium carbonate/cholecalciferol association (1500 mg + 400 UI) and calcitriol 0.25 mg with daily doses being titrated to 9000 mg of calcium carbonate and 1.25 mg of calcitriol daily in order to achieve a serum calcium of 8-8.4 mg/dl and a normal serum phosphorus. At a scheduled revaluation, the patient presented with hypercalcemia (serum calcium of 13.9 mg/dl), acute renal failure (serum creatinine of 2.72 mg/dl), and metabolic alkalosis (pH of 7.52, pCO2 46.3 mmHg and HCO3 29.2 mmol/l). The patient denied anti-inflammatory medication, nausea and vomiting, fever, respiratory or gastrointestinal symptoms. Hypoparathyroidism treatment was stopped and the patient was admitted to the hospital. Intravenous fluid replacement was started with a slow gradual renal function recovery and calcium normalization. Malignant hypercalcemia was excluded with whole body CT scan, PTHrP measurement and serum PSA. Angiotensin converting enzyme and serum immunofixation were normal. Patient denied frequent consumption of antacids or canned or preserved foods but admitted to daily consumption of calcium enriched milk. MAS diagnosis was assumed. Calcium carbonate and calcitriol were restarted at lower dosages, and dietary counselling was made. Patient maintained desired calcium levels with 4500 mg of calcium carbonate 1 mg of calcitriol.

Conclusion: This case highlights that MAS is a possible complication of hypoparathyroidism treatment. Calcium and vitamin D supplementation should be tailored to individual patients and a closer monitoring may be needed in patients under higher daily doses.