Endocrine Abstracts

JOINT1445

Background: Hypocalcemia is a common complication of thyroidectomy, often necessitating hospitalization for calcium supplementation. Previous studies yielded contradictory results on whether cholecalciferol prevents postoperative hypocalcemia, and most were conducted in non-Western countries with different dietary habits and baseline vitamin D levels. Therefore, we aimed to investigate the effect of preoperative cholecalciferol on post-thyroidectomy hypocalcemia in a Dutch population.

Methods: Patients who underwent thyroidectomy between 2023-2025 received 100,000 IU cholecalciferol one week preoperative (‘vitamin D group’) and were compared to a historical cohort (2019-2022) who did not receive cholecalciferol supplementation (‘control group’). Outcomes included incidence of post-thyroidectomy hypocalcemia (<2.00 mmol/l, 24h,48h,72h,>72h postoperative), need for postoperative supplementation, time until normocalcemia, length of hospital stay, and hospital readmission.

Results: Fifty patients received preoperative cholecalciferol and were compared to 154 control patients (82.8% female, median age: 55 years [IQR:43-66]). Hypocalcemia occurred less frequently in the vitamin D group (cumulative incidence: 16.0% vs. 35.1%, P = 0.01 for biochemical and 12.0% vs. 24.0%, P = 0.07 for symptomatic hypocalcemia). Preoperative cholecalciferol supplementation was associated with a reduced risk of hypocalcemia (OR 0.27,95%CI:0.11-0.68, P = 0.005). Furthermore, the vitamin D group demonstrated a lower need for postoperative supplementation (32.0% vs. 53.9%, P = 0.007) and faster recovery to normocalcemia (0[0-2] vs. 3[0-11] days, P = 0.002). No differences were observed in length of hospital stay and hospital readmissions.

Conclusion: A preoperative dose of 100,000 IU cholecalciferol was associated with a significant reduction in post-thyroidectomy hypocalcemia. With a number needed to treat of 5 patients to prevent one case of hypocalcemia, this inexpensive and safe intervention could be considered for routine use in patients undergoing thyroidectomy.