Endocrine Abstracts

Introduction: Milk-Alkali Syndrome (MAS), also known as Burnett’s syndrome, is a triad of hypercalcemia, acute kidney injury and metabolic alkalosis, traditionally associated with excessive intake of milk and absorbable alkali. With changes in dietary supplements and medical prescriptions, its re-presentation in modern clinical practice has evolved making it the third common cause for hypercalcemia. This abstract presents a unique case of MAS resulting from relatively supraphysiological doses of calcium supplements in a patient with a low body mass index (BMI).

Case presentation: A woman in her early 60s presented with symptoms including confusion, constipation, excessive thirst, and tiredness. She has chronic excessive alcohol intake, self-neglect, and poor oral nutritional intake. Three years prior to this admission, following low-velocity falls resulting in fractures, she was started on calcium and vitamin D supplementation containing 500 mg of calcium carbonate and 400 IU of cholecalciferol. Given her extremely low BMI of 10.59 kg/m², she was supplemented with Fortisip which contains additional calcium. On examination, she appeared severely emaciated with dry mucous membranes and signs of dehydration. Laboratory findings indicated a significantly low parathyroid hormone (PTH) level, elevated albumin corrected calcium, low magnesium and phosphate levels, and normal 25-hydroxy vitamin D. Her serum bicarbonate was extremely elevated. A full-body CT scan showed multiple bladder calculi with no evidence of underlying malignancy.

Discussion: The patient’s medical history and acute presentation led to the diagnosis of MAS, primarily due to her high intake of calcium carbonate relative to her body weight, as evidenced by her metabolic alkalosis despite acute kidney injury. Upon discontinuation of calcium supplements, her PTH rose to 33.1 pmol/l, while calcium levels dropped to 2.16 mmol/l. MAS is classified into three types based on symptom duration and organ dysfunction: acute MAS or toxemic form, sub-acute form or Cope’s syndrome, and chronic form or Burnett’s syndrome. This case emphasizes the importance of individualized patient care, especially in managing dietary supplements, and highlights the potential risks of excessive calcium intake in patients with low BMI. It also stresses the need for vigilant monitoring of calcium and PTH levels to prevent recurrent hypercalciuria and kidney stone formation.