Tehran University of Medical Sciences (TUMS) Academic Journal of Surgery 2423-3218 3 3-4 2017 03 26 54 57 EN Alireza Khazaii Department of Surgery, School of Medicine AND Imam Ali Hospital, Zahedan University of Medical Sciences, Zahedan, Iran Mahdie Ramazani Department of Surgery, School of Medicine AND Imam Ali Hospital, Zahedan University of Medical Sciences, Zahedan, Iran 2016 11 26 2017 03 26 Background: Post-operative transient hypocalcemia is a common event after total thyroidectomy. It may reveal permanent hypoparathyroidism following total or subtotal thyroidectomy. It has been hypothesized that there is a relationship between underlying vitamin D deficiency and the risk of post-operative hypocalcemia. Methods: We performed a cross-sectional review on 100 thyroidectomies from 2016 at an academic teaching hospital. Pre-operative vitamin D levels and post-operative calcium level were obtained. The incidence of hypocalcemic symptoms was studied. Biochemical hypocalcemia was defined as any single post-operative corrected calcium level < 8.0 mg/dl (to convert to millimoles per liter, multiply by 0.25). Results: Post-operative calcemia < 8.0 mg/dl was observed in 19 patients (19%). We found that the patients carried a high risk for post-operative transient biochemical hypocalcemia if the pre-operative serum vitamin D levels ˂ 35 nmol/L. There was a significant differentiation between mean of vitamin D levels in hypocalcemic group and normocalcemic group. Conclusions: Pre-operative vitamin D levels appear to have a significant effect on the risk of post-thyroidectomy hypocalcemia. https://ajs.tums.ac.ir/index.php/ajs/article/view/80 https://ajs.tums.ac.ir/index.php/ajs/article/download/80/50