Does preoperative 25-hydroxyvitamin D status significantly affect the calcium kinetics after total thyroidectomy?

Area of Science:

• Endocrinology
• Surgical Oncology
• Nutritional Science

Background:

• Low preoperative 25-hydroxyvitamin D (25-OHD) is linked to hypocalcemia post-thyroidectomy.
• Immediate postoperative calcium (Ca) and parathyroid hormone (PTH) kinetics relative to 25-OHD levels are not well understood.

Purpose of the Study:

• To investigate the impact of preoperative 25-hydroxyvitamin D (25-OHD) levels on calcium (Ca) and parathyroid hormone (PTH) kinetics in the early postoperative period following total thyroidectomy.

Main Methods:

• 281 patients undergoing total thyroidectomy were stratified into three groups based on preoperative 25-OHD levels (<10, 10-20, >20 ng/mL).
• Serum Ca and PTH levels were measured preoperatively, and at 0 and 1 day postoperatively.
• Ca/PTH kinetics and Ca drop were compared between the groups.

Main Results:

• Patients with the lowest 25-OHD (<10 ng/mL) had lower preoperative and immediate postoperative Ca, but higher postoperative PTH on day 1.
• No significant differences were observed in PTH on day 0, Ca on day 1, or clinically significant hypocalcemia rates.
• The lowest 25-OHD group exhibited a smaller Ca drop and a trend towards a smaller PTH drop compared to other groups.

Conclusions:

• Despite starting with lower calcium, patients with low preoperative 25-OHD demonstrated a robust PTH response to calcium fluctuations.
• Preoperative 25-OHD levels did not significantly alter overall calcium kinetics from pre-operation to postoperative day 1.