Total thyroidectomy is a commonly performed surgery for thyroid diseases such as multinodular goiter. One of the most frequent complications after this procedure is hypocalcemia (low blood calcium levels), which may cause symptoms such as tingling around the mouth, muscle cramps, and in severe cases, spasms or confusion. This condition usually occurs within the first 24-72 hours after surgery and may delay hospital discharge and increase patient discomfort.

This study aims to compare the effectiveness of preoperative calcium plus vitamin D3 supplementation versus calcium supplementation alone in preventing postoperative symptomatic hypocalcemia in patients undergoing total thyroidectomy. Patients diagnosed with multinodular goiter and planned for surgery will be randomly assigned into two groups. One group will receive calcium with vitamin D3 for seven days before surgery, while the other group will receive calcium alone for the same duration.

After surgery, patients will be monitored for symptoms of hypocalcemia and their serum calcium levels will be checked at 6, 24, and 48 hours, as well as at a follow-up visit on day 14. The main outcome of the study is the occurrence of symptomatic hypocalcemia in both groups.

The results of this study may help determine whether adding vitamin D3 to preoperative calcium supplementation provides better protection against hypocalcemia after thyroid surgery, potentially improving patient outcomes and reducing hospital stay.

Total thyroidectomy is a standard surgical procedure performed for benign and malignant thyroid disorders, particularly multinodular goiter. Despite being a safe operation, one of its most common and clinically significant complications is postoperative hypocalcemia, which primarily results from transient or permanent impairment of parathyroid gland function due to devascularization, inadvertent removal, or surgical trauma. Symptomatic hypocalcemia typically occurs within 24-72 hours after surgery and may present with neuromuscular irritability such as perioral numbness, paresthesia, muscle cramps, carpopedal spasm, tetany, or, in severe cases, cardiac arrhythmias. This complication can lead to prolonged hospital stay, increased patient morbidity, and higher healthcare costs.

Various strategies have been proposed to reduce the incidence and severity of post-thyroidectomy hypocalcemia, including routine postoperative calcium supplementation, selective supplementation based on serum calcium or parathyroid hormone levels, and preoperative administration of calcium and vitamin D3. Vitamin D3 plays a key role in calcium homeostasis by enhancing intestinal calcium absorption and improving postoperative calcium balance, potentially reducing the risk of symptomatic hypocalcemia when administered preoperatively along with calcium.

This randomized controlled trial is designed to compare the efficacy of preoperative calcium plus vitamin D3 supplementation versus calcium supplementation alone in preventing postoperative symptomatic hypocalcemia in euthyroid patients undergoing total thyroidectomy for multinodular goiter. Eligible patients will be randomized into two groups: one receiving oral calcium with vitamin D3 and the other receiving oral calcium alone for seven days prior to surgery.

Postoperatively, patients will be closely monitored clinically and biochemically. Serum corrected calcium levels will be measured at 6, 24, and 48 hours after surgery, and again at a 14-day follow-up visit. Parathyroid hormone levels will also be assessed at selected time points. Symptomatic hypocalcemia will be defined based on the presence of clinical features in combination with low serum calcium levels.

The study aims to determine whether preoperative vitamin D3 supplementation provides additional benefit over calcium alone in reducing the incidence of postoperative symptomatic hypocalcemia, thereby improving early postoperative recovery, reducing hospital stay, and optimizing perioperative management in thyroid surgery patients.

Inclusion Criteria:

• A) Age between 18 to 60 years B) Both genders C) Multiple nodular goiter diagnosed on the basis of history and investigation like thyroid function test , USG neck for TIRADS scoring and USG guided FNAC to confirm the diagnosis .

D) ASA grade 1 &2 E) With preserved one or two parathyroid gland

Exclusion Criteria:

• A) Cardiovascular disease B) Deranged Renal parameters C) Pregnancy D) Concomitant endocrine pathology warranting the surgery

Individual participant data will not be shared as this is a single-center academic research study conducted for institutional and postgraduate training purposes. Data will remain confidential and will be used only for analysis and publication within the study team, in accordance with institutional ethical review board guidelines and patient confidentiality policies.