Preoperative Vitamin.D Status and Post-Total Thyroidectomy Hypocalcemia

Hypocalcemia is a common complication of total thyroidectomy (TT). This study was designed to investigate the effect of preoperative vitamin.D (Vit.D) status on the occurrence of post-total thyroidectomy hypocalcemia.

Patients who underwent TT without parathyroidectomy were divided into three groups based on their preoperative Serum Vit.D levels (<20 ng/ml, 20-30 ng/ml, and ≥30 ng/ml were considered deficient, insufficient, and normal Vit.D levels, respectively). Serum levels of calcium and phosphorus were measured before and 24 hours after surgery in all patients. The patients were examined for clinical symptoms and signs of hypocalcemia postoperatively. In cases with positive clinical symptoms and signs of hypocalcemia and/or calcium levels <8 mg/dl, PTH level was measured before starting calcium infusion, while serum calcium and phosphorus levels were also measured 24 hours later.

Among 100 patients enrolled in this study, 81% were females. The mean age was 36.60±8.32 years. Before surgery, the mean Vit.D level was 26.9±16.89 ng/ml, while 47% of cases had normal Vit.D level, 32% had insufficient vitamin levels, and 21% had Vit.D deficiency. Twenty-four hours after surgery, the calcium (P=0.356) and phosphorus (P=0.743) levels were not significantly different between the three Vit.D groups. A comparison of postoperative PTH levels between the three Vit.D groups showed no significant difference (P=0.596).

Based on our findings, preoperative serum Vit.D levels did not affect postoperative serum calcium levels.