en Endocrinology Endocrinology Original Article Original Article <p align="left"> <font face="Times New Roman" size="3"> </font><font face="Times New Roman"><b><i><span lang="EN-US" style="color: blue font-size: 10pt">Background: </span></i></b><span lang="EN-US" style="color: black font-size: 10pt">Hypocalcemia is a well-recognized complication after total thyroidectomy. Hypovitaminosis D may have additional effect in the development of hypocalcemia. This study aimed to determine the effect of total thyroidectomy on postoperative serum calcium in patients with and without hypovitaminosis D.</span><b><i><span lang="EN-US" style="color: blue font-size: 10pt"><o:p /></span></i></b></font></p><p align="left"><font face="Times New Roman" size="3"> </font><font face="Times New Roman"><b><i><span lang="EN-US" style="color: blue font-size: 10pt">Methods:</span></i></b><span lang="EN-US" style="font-size: 10pt"> <span style="color: black"><font size="2">This prospective study was performed on patients who underwent total thyroidectomy from 2011 to 2014 in Imam Khomeini General Hospital of Mazandaran University of Medical Sciences. Serum calcium and vitamin D values were recorded before and after surgery. The patients were classified according to serum vitamin D concentrations as less 10 ng/ml (vitamin D deficiency) or higher (control group). The mean values of postoperative calcium level for each class of serum vitamin D were determined and compared. Hypocalcemia was defined as a postoperative calcium level <8 mg/dl.<span class="longtext"><span style="background: white"><o:p /></span></span></font></span></span></font></p><p align="left"><font face="Times New Roman" size="3"> </font><font face="Times New Roman"><b><i><span lang="EN-US" style="color: blue font-size: 10pt">Results:</span></i></b><span lang="EN-US" style="font-size: 10pt"> <span style="color: black"><font size="2">125 patients due to thyroid disease underwent total thyroidectomy. The incidence of symptomatic and asymptomatic hypocalcemia after surgery was 12% (n=15) and 3.2% (n=4) respectively. 82 (65.6%) patients had vitamin D deficiency and 43 (34.4%) patients had sufficient vitamin D level. There was not any significant difference in calcium level (8.67±0.58 mg/dl vs. 8.70±0.59 mg/dl) between two vitamin D studied groups after thyroid surgery (p>0.05).<span class="longtext"><span style="background: white"><o:p /></span></span></font></span></span></font></p><p align="left"><font face="Times New Roman" size="3"> </font><font face="Times New Roman"><b><i><span lang="EN-US" style="color: blue font-size: 10pt">Conclusion: </span></i></b><span lang="EN-US" style="color: black font-size: 10pt">The findings of this study indicated that vitamin D deficiency had no significant effect on post-thyroidectomy serum calcium level.</span><span lang="EN-US" style="font-size: 10pt"> <o:p /></span></font></p><p align="left"><font face="Times New Roman" size="3"> </font></p> Hypocalcemia, Transient hypocalcemia, Vitamin D deficiency, Thyroidectomy, Hypoparathyroidism 72 76 http://caspjim.com/browse.php?a_code=A-10-248-1&slc_lang=en&sid=1 Gholamali Godazandeh 10031947532846002966 10031947532846002966 No Department of Thoracic Surgery, Imam Khomeini Hospital, Mazandaran University of Medical Sciences, Sari, Iran Zahra Kashi zkashi@mazums.ac.ir 10031947532846002967 10031947532846002967 Yes Diabetes Research Center, Mazandaran University of Medical Sciences, Sari, Iran Farnaz Godazandeh 10031947532846002968 10031947532846002968 No Department of Radiology, Imam Khomeini Hospital , Mazandaran University of Medical Sciences, Sari, Iran. Pouya Tayebi 10031947532846002969 10031947532846002969 No Department of Thoracic Surgery, Imam Khomeini Hospital, Mazandaran University of Medical Sciences, Sari, Iran. Ali Bijani 10031947532846002970 10031947532846002970 No Social Determinant of Health Research Center, Babol University of Medical Sciences, Babol, Iran.