Unmasking normocalcaemic hyperparathyroidism (nPHPT) resulting in severe hypercalcaemia from lack of monitoring during in the COVID pandemic

Primary hyperparathyroidism (PHPT) is a common endocrine disorder in the older person although the incidence of normocalcaemic primary hyperparathyroidism (nPHPT) remains largely unknown. Whilst the majority of patients with PHPT asymptomatic, we describe a case of severe symptomatic hypercalcaemia from undiagnosed nPHPT whilst on calcium and vitamin D supplements. This is an important reminder to clinicians that serum calcium should be monitored before and after initiation of calcium and vitamin D supplementation in the older person.