ObjectiveTo introduce patients with long-term hypocalcemia and normal parathyroid hormone (PTH) values after total thyroidectomy, and to analyze the possible causes of this phenomenon. MethodsThe medical records of 1 010 consecutive patients with total thyroidectomy treated in the Center for Diagnosis and Treatment of Thyroid Disease, the First Affiliated Hospital of Kunming Medical University from January 2019 to December 2020 were collected. Seven patients with normal PTH and blood calcium before operation and at least 2 times of PTH with hypocalcemia detected more than 6 months after operation were followed-up to understand the symptoms of hypocalcemia, vitamin D level and calcium consumption. ResultsSeven patients with thyroid papillary carcinoma underwent total thyroidectomy without parathyroid autotransplantation, and there were 6 cases with mild deficiency or insufficient of vitamin D before operation. The follow-up time was 12–28 months, and the median follow-up time was 19 months. Seven patients developed hypocalcemia after continuous administration of calcium and calcitriol, and vitamin D levels remained mild deficiency or insufficient, PTH decreased by more than 50% in 6 patients one year after operation compared with that before operation. ConclusionsPatients with long-term normal PTH values and hypocalcemia after total thyroidectomy have obviously lower PTH levels than those before operation. The possible factors are parathyroid damage during operation and vitamin D deficiency. Such these patients should be more properly referred to as “parathyroid insufficiency”.