Vitamin D cannot be used as a global predictor of post-thyroidectomy hypocalcaemia

To assess the relationship between vitamin D and post-operative hypocalcaemia in patients undergoing total thyroidectomy in our population.

A prospective cohort of 210 patients meeting inclusion criteria from March 2020 to September 2023 at Sultan Qaboos University Hospital was analysed. Pre-operative serum 25-hydroxy vitamin D was measured, with calcium and parathyroid hormone assessed post-operatively, and symptoms recorded.

Univariate and logistic regression analyses showed no significant association between pre-operative vitamin D levels and post-operative hypocalcaemia (p = 0.254 and 0.52, respectively). Receiver operating characteristic analysis showed an area under the curve of 0.6 (p = 0.012), indicating limited predictive ability.

In our population, pre-operative vitamin D level was not a reliable predictor of post-thyroidectomy hypocalcaemia. Because of population-based differences in vitamin D metabolism and assay variability, universal cut-off values remain impractical. These findings highlight the need for further research to establish population-specific thresholds for vitamin D in predicting hypocalcaemia risk.