A puzzling case of phospho-soda-induced hypocalcemia in a patient with multiple endocrine neoplasia type 1-associated primary hyperparathyroidism.

Although rare, symptomatic hypocalcemia may develop after the administration of phospho-soda. We herein present the case of a patient with phospho-soda-induced hypocalcemia who was surprisingly diagnosed with multiple endocrine neoplasia type 1 (MEN1) caused by a heterozygous mutation in the MEN1 gene (c628_631delACAG), thus resulting in a frameshift mutation (210ThrfsX224). In addition to being the first report of phospho-soda-induced hypocalcemia in a patient with MEN1-associated primary hyperparathyroidism, our report highlights the complex nature of calcium balance in the human body and helps clinicians to appreciate how confounding factors might affect the presentation of endocrine disorders.