Publication:

Correlation of pre-operative vitamin D3 levels with post-operative hypocalcemia in patients undergoing total thyroidectomy

Background Total thyroidectomy (TT) is a commonly performed procedure for various  thyroid disorders, with parathyroid insufficiency manifesting as hypocalcaemia being a well-known complication. Albeit, vitamin D is well implicated in calcium homeostasis, the association between hypovitaminosis D and postoperative hypocalcaemia is yet to be concluded. The aim of our study is to evaluate the correlation of preoperative serum vitamin D3 levels  with occurrence of post-operative hypocalcemia in patients undergoing TT.

Methods A prospective  study  was conducted on 50 patients  undergoing TT for benign thyroid diseases from November 2016 to May 2018. Pre-operative vitamin D3 levels were estimated. Serum calcium levels was measured pre‑ and post‑operatively at 24hours, 1st week and 4th week. Serum calcium level ≤8.5 mg/dl was considered as biochemical hypocalcemia. A data of demographic, clinical, biochemical and intraoperative findings were documented and analysed.

Results Statically 14 (28%) patients developed symptomatic hypocalcemia. Out of these, 11 (78.5%) patients had preoperative vitamin D levels of <30 ng/dl (p=0.034). 24 hours postoperative serum calcium level was significantly  lesser in patients with  lower preoperative vitamin D levels (p=0.015), suggesting that postoperative  hypocalcemia (24 hr) is statistically related to pre-operative vitamin D3 levels.

Conclusions It could be concluded from our study that preoperative serum vitamin D3 levels can predict post-operative occurrence of symptomatic and/or biochemical hypocalcemia. Thus, it could be hypothesized that supplementing vitamin D preoperatively could curb the incidence of hypocalcaemia following TT. However, further relevant trials are needed to attest to this.