title: Severe vitamin D deficiency: a significant predictor of early hypocalcemia after total thyroidectomy.
abstract: OBJECTIVE
  To assess the role of preoperative serum 25 hydroxyvitamin D as predictor of hypocalcemia after total thyroidectomy.
  
  
  METHODS
  Retrospective cohort study.
  
  
  METHODS
  University teaching hospital.
  
  
  METHODS
  All consecutively performed total and completion thyroidectomies from February 2007 to December 2013 were reviewed through a hospital database and patient charts. The relationship between postthyroidectomy laboratory hypocalcemia (serum calcium≤2 mmol/L), clinical hypocalcemia, and preoperative serum 25 hydroxyvitamin D level was evaluated.
  
  
  RESULTS
  Two hundred thirteen patients were analyzed. The incidence of postoperative laboratory and clinical hypocalcemia was 19.7% and 17.8%, respectively. The incidence of laboratory and clinical hypocalcemia among severely deficient (<25 nmol/L), deficient (<50 nmol/L), insufficient (<75 nmol/L), and sufficient (≥75 nmol/L) serum 25 hydroxyvitamin D levels was 54% versus 33.9%, 10% versus 18%, 2.9% versus 11.6%, and 3.1% versus 0%, respectively. Multiple logistic regression analysis revealed preoperative severe vitamin D deficiency as a significant independent predictor of postoperative hypocalcemia (odds ratio [OR], 7.3; 95% confidence interval [CI], 2.3-22.9; P=.001). Parathyroid hormone level was also found to be an independent predictor of postoperative hypocalcemia (OR, 0.6; 95% CI, 0.5-0.8; P=.002).
  
  
  CONCLUSIONS
  Postoperative clinical and laboratory hypocalcemia is significantly associated with low levels of serum 25 hydroxyvitamin D. Our findings identify severe vitamin D deficiency (<25 nmol/L) as an independent predictor of postoperative laboratory hypocalcemia. Early identification and management of patients at risk may reduce morbidity and costs.
authors.affiliation: Department of Otolaryngology-Head and Neck Surgery, Faculty of Medicine, King Abdulaziz University, Jeddah University, Jeddah, Saudi Arabia.
authors.forename: Talal
authors.initials: T
authors.lastname: Al-Khatib
authors.affiliation: Department of Otolaryngology-Head and Neck Surgery, Faculty of Medicine, King Abdulaziz University, Jeddah University, Jeddah, Saudi Arabia dr_amt@live.com.
authors.forename: Abdulrahman M
authors.initials: AM
authors.lastname: Althubaiti
authors.affiliation: Department of Basic Medical Sciences, College of Medicine, King Saud bin Abdulaziz University for Health Sciences, Riyadh, Saudi Arabia.
authors.forename: Alaa
authors.initials: A
authors.lastname: Althubaiti
authors.affiliation: Department of Medicine, Endocrinology and Metabolism Division, King Abdulaziz University, Jeddah, Saudi Arabia.
authors.forename: Hala H
authors.initials: HH
authors.lastname: Mosli
authors.affiliation: Faculty of Medicine, King Abdulaziz University, Jeddah, Saudi Arabia.
authors.forename: Reem O
authors.initials: RO
authors.lastname: Alwasiah
authors.affiliation: Faculty of Medicine, King Abdulaziz University, Jeddah, Saudi Arabia.
authors.forename: Lojain M
authors.initials: LM
authors.lastname: Badawood
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002118:Calcium / Q000097:blood*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D006996:Hypocalcemia / Q000097:blood / Q000453:epidemiology / Q000209:etiology*; D015994:Incidence; D008297:Male; D008875:Middle Aged; D011183:Postoperative Complications; D011184:Postoperative Period; D011379:Prognosis; D012189:Retrospective Studies; D012307:Risk Factors; D012529:Saudi Arabia / Q000453:epidemiology; D012720:Severity of Illness Index; D013959:Thyroid Diseases / Q000601:surgery; D013965:Thyroidectomy / Q000009:adverse effects*; D013997:Time Factors; D014807:Vitamin D / Q000031:analogs & derivatives* / Q000097:blood; D014808:Vitamin D Deficiency / Q000097:blood / Q000150:complications* / Q000175:diagnosis; D055815:Young Adult
chemical_list: D014807:Vitamin D; C104450:25-hydroxyvitamin D; D002118:Calcium
keywords: hypocalcemia; low 25(OH)D; thyroidectomy; vitamin D deficiency