Vitamin D level is not a predictor of hypocalcemia after total thyroidectomy

As the incidence of thyroid cancer has increased, hypocalcemia, a common complication of thyroid surgery, has become a serious problem. However, no definite predictor of postoperative hypocalcemia is known. In this study, our purpose was to investigate the potential role of vitamin D as a predictor of postoperative hypocalcemia.

A prospective observational study was performed on patients who underwent total thyroidectomy for thyroid cancer performed by a single experienced surgeon between October 2013 and September 2014.

Their serum 25-OH vitamin D levels were measured preoperatively. On the day after surgery, serum calcium and intact parathyroid hormone levels were measured, and symptoms of hypocalcemia were recorded.

Of the 134 patients, laboratory and symptomatic hypocalcemia developed in 52 patients (39 %) and 25 patients (19 %), on the day after surgery. The preoperative vitamin D level was 16.5 ± 9.2 ng/mL, and this value did not differ according to laboratory or symptomatic hypocalcemia (p = 0.94). The incidence of laboratory or symptomatic hypocalcemia did not differ according to vitamin D deficiency. Only incidental parathyroidectomy was associated with symptomatic hypocalcemia (p = 0.03).

Vitamin D level is not a predictor of hypocalcemia after total thyroidectomy for thyroid cancer. Thus, routine preoperative screening for vitamin D is not recommended.