Role of oral calcium supplementation alone or with vitamin D in preventing post-thyroidectomy hypocalcaemia A meta-analysis

Background: Thyroidectomy is the main intervention for thyroid malignancies and some benign thyroid diseases. Its most common complication is hypocalcaemia, which requires oral or intravenous calcium therapy. The aim of this meta-analysis was to assess the efficacy of routine calcium supplementation with or without vitamin D in preventing hypocalcaemia post-thyroidectomy. Methods: Systematic searches of the PubMed, EMBASE, and Cochrane Library databases were performed. The qualities of the included articles were assessed using the Cochrane risk of bias tool. The studies' qualities of outcomes and strengths of evidence were evaluated using the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) tool. Data analysis was performed using Review Manager 5.3, and odds ratio (ORs) with their 95% confidence intervals (CIs) were computed for dichotomous data. Results: Ten randomized controlled trials (RCTs) were included. The combined study recruited 1620 patients (343 men and 1277 women) who underwent total thyroidectomy alone or with neck dissection. Calcium supplementation decreased the risk of transient postoperative hypocalcaemia (OR 0.48 [95% CI, 0.31-0.74]; P<.001) but did not decrease the demand for intravenous supplementation or the rate of permanent hypocalcaemia compared to no treatment. Calcium and vitamin D supplementation significantly reduced the rate of transient hypocalcaemia and the demand for intravenous supplementation compared to either no treatment (OR 0.21 [95% CI, 0.11-0.40]; P<.001 and OR 0.26 [95% CI, 0.10-0.69]; P=.007, respectively) or calcium alone (OR 0.39 [95% CI, 0.18-0.84]; P=.02 and OR 0.18 [95% CI, 0.07-0.47]; P<.001, respectively), but did not decrease the rate of permanent hypocalcaemia. GRADE-based confidence was moderate. Conclusion: Postoperative calcium supplementation is effective for preventing post-thyroidectomy hypocalcaemia. Calcium plus vitamin D was more effective than calcium alone in preventing postoperative hypocalcaemia and decreasing the demand for intravenous calcium supplementation. Further, well-designed RCTs with larger sample sizes are required to validate our findings.