Prevention of Postoperative Hypocalcemia of Oral Vitamin D Supplementation Before Total Thyroidectomy

The hypocalcemia after total thyroidectomy is one of common surgical complications. It may be asymptomatic, but patients can complain of dysfunction around the mouth or extremities, stiffness or convulsion in severe cases. The incidence of transient hypocalcemia was 6.9-46%, and permanent hypocalcemia was reported to be 0.4-33%. It has been reported that the incidence of hypocalcemia after thyroidectomy is high when the difference in blood levels of parathyroid hormone and vitamin D is large before and after surgery. Therefore, it is a very important task to study the effect of using vitamin D3 (cholecalciferol), which has a better effect on the human body, on the prevention of hypocalcemia after total thyroidectomy with a long follow-up period after surgery. The department of surgery in Seoul National University Hospital intends to analyze the preventive effect "D-mac 30,000 IU" on postoperative hypocalcemia and safety of 'D-mac 30,000 IU" through a prospective randomized clinical trial. The incidence of postoperative hypocalcemia of the group taking orally taking vitamin D3 (cholecalciferol) before surgery will be compared with that of the group not taking vitamin D3 before surgery. Patients who are enrolled in this RCT are allocated to the case group and the control group. Patients in the case group are taking 30,000 IU of vitamin D3 (cholecalciferol) orally, and patients in the control group are not taking any drugs. Primary endpoint of this study is to evaluate the incidence of hypocalcemia. And secondary endpoints are to evaluate the recovery duration from postoperative hypocalcemia and the risk factors for postoperative hypocalcemia.