Preoperative calcium and vitamin D supplementation may reduce postoperative hypocalcaemia after total thyroidectomy

Hypocalcaemia is the most common postoperative complication after total thyroidectomy. The purpose of the study was to evaluate the clinical usefulness of routine preoperative oral calcium and vitamin D supplementation in the prevention of hypocalcaemia after total thyroidectomy.

One hundred and fifty-three consecutive patients with nontoxic multinodular goitre were randomly assigned to routinely receive (group B) or not receive (group A) calcium carbonate (3 g/day) and alfacalcidol (1 µg/day) on the day before surgery and calcium carbonate (1 g/day) and alfacalcidol (1 µg/day) taken once in the morning on the day of the operation. Their preoperative 25-hydroxyvitamin D (25-OHD) levels, hypocalcaemic symptoms, serum calcium and parathyroid hormone (iPTH) levels were determined 6 and 24 h and 6 weeks after surgery.

Symptomatic hypocalcaemia was observed in 41/153 (26.79%) patients. The incidence of symptomatic hypocalcaemia was significantly lower in the supplemented group than in the group not receiving supplementation: 10 of 77 participants (12.99%) versus 31 of 76 patients (40.79%) (p < 0.05). The rates of laboratory and severe hypocalcaemia (corrected calcium < 2.0 mmol/l) were 67.11% and 28.95% in group A and 50.65% and 9.09% in group B, respectively (p = 0.04, p < 0.05). There were no significant differences between groups A and B in corrected calcium levels after surgery and postoperative decreases in corrected calcium levels (p = 0.06). 112 (73.20%) participants had 25-OHD < 20 ng/ml. Vitamin D levels did not influence corrected calcium level changes (p = 0.98).

Oral supplementation with calcium and alfacalcidol may reduce post-thyroidectomy hypocalcaemia. Vitamin D deficiency was common among the study population.