Introduction Transient hypocalcemia is a common complication after total thyroidectomy. The objective of this retrospective study was to evaluate the clinical usefulness of vitamin D injection before operation for the prevention of postoperative transient hypocalcemia.
Methods 2294 patients who underwent total thyroidectomy from January 2015 until October 2018 were analyzed retrospectively by complete chart review at Severance Hospital (Seoul, Korea). The patients were divided into two groups - vitamin D injection (VDI) group [n=342] and vitamin D non-injection (VDN) group [n=1952]. Transient hypocalcemia was defined as serum calcium <8.2mg/dL and signs or symptoms of hypocalcemia.
Results The mean preoperative vitamin D level of VDI group was significantly lower than that of VDN group (16.5 ± 6.9 ng/mL vs. 19.4 ± 8.7 ng/mL, p<0.001). Multivariate analysis indicated that the significant risk factors of postoperative transient hypocalcemia include vitamin D non-injection (hazard ratio [HR]: 1.717, 95% confidence interval [CI]: 1.282-2.300, p<0.001), male gender (HR: 1.427, 95% CI: 1.117-1.822, p=0.004), and capsular extension (HR: 1.273, 95% CI: 1.011-1.603, p=0.040).
Conclusion Preoperative vitamin D injection effectively prevents postoperative transient hypocalcemia after total thyroidectomy. Further studies must be conducted to determine the effect of vitamin D injection.