All participating patients will be randomised into intervention and placebo arm with 1:1 ratio. Intervention group will receive 1 ampoule of intravenous calcium gluconate within 4 hours of post total thyroidectomy, whereas the placebo group will received 100ml of normal saline only. Both groups will receive same oral calcium supplements post surgery. Both groups will have their serum calcium measure at 6,12,24,36,48-hour mark post surgery.

