Parvin Layegh - Metabolic Syndrome Research Center, Mashhad University of Medical Sciences, Mashhad, Iran.
Zakie Sadat Sajjadi - Department of Otorhinolaryngology, Imam Reza Hospital, Mashhad University of Medical Sciences, Mashhad, Iran.
Leila V.Mostaan - Cancer Research Center, Mashhad University of Medical Sciences, Mashhad, Iran.
Masoud Mohebbi - Metabolic Syndrome Research Center, Mashhad University of Medical Sciences, Mashhad, Iran.
Mona Kabiri - Nanotechnology Research Center, Pharmaceutical Technology Institute, Mashhad University of Medical Sciences, Mashhad, Iran.
Mohammad ali Yaghoubi - Metabolic Syndrome Research Center, Mashhad University of Medical Sciences, Mashhad, Iran.

Introduction: 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.Materials and Methods: Patients who underwent TT without parathyroidectomy were divided into three groups based on their preoperative Serum Vit.D levels (<۲۰ ng/ml, ۲۰-۳۰ ng/ml, and ≥۳۰ ng/ml were considered deficient, insufficient, and normal Vit.D levels, respectively). Serum levels of calcium and phosphorus were measured before and ۲۴ 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 <۸ mg/dl, PTH level was measured before starting calcium infusion, while serum calcium and phosphorus levels were also measured ۲۴ hours later.Results:Among ۱۰۰ patients enrolled in this study, ۸۱% were females. The mean age was ۳۶.۶۰±۸.۳۲ years. Before surgery, the mean Vit.D level was ۲۶.۹±۱۶.۸۹ ng/ml, while ۴۷% of cases had normal Vit.D level, ۳۲% had insufficient vitamin levels, and ۲۱% had Vit.D deficiency. Twenty-four hours after surgery, the calcium (P=۰.۳۵۶) and phosphorus (P=۰.۷۴۳) 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=۰.۵۹۶).Conclusions:Based on our findings, preoperative serum Vit.D levels did not affect postoperative serum calcium levels.

Hypocalcemia, Vitamin.D, Total thyroidectomy