title: Vitamin D and risk of postoperative hypocalcemia after total thyroidectomy.
abstract: OBJECTIVE
  Transient hypocalcemia is a well-recognized occurrence after total thyroidectomy. It has been hypothesized that underlying vitamin D deficiency may increase the risk of this complication, although to date there are few data in the literature supporting this hypothesis.
  
  
  OBJECTIVE
  To investigate whether perioperative vitamin D levels have any effect on postthyroidectomy hypocalcemia.
  
  
  METHODS
  We performed a retrospective review of a prospectively maintained database of thyroidectomies from November 1, 2009, through September 30, 2012, at an academic teaching hospital. The study included 121 patients with available vitamin D levels undergoing total or completion thyroidectomy. Patients with preexisting hypercalcemia or hyperparathyroidism were excluded.
  
  
  METHODS
  All patients underwent total removal of all thyroid tissue by a capsular dissection technique. Routine calcium or vitamin D supplementation was not administered. Biochemical hypocalcemia was defined as any single postoperative corrected calcium level less than 8.0 mg/dL (to convert to millimoles per liter, multiply by 0.25) and symptomatic hypocalcemia as any symptoms of hypocalcemia.
  
  
  METHODS
  Outcome measures were incidence of postoperative hypocalcemia and association with vitamin D levels. A multivariate analysis was performed to study the effect of other variables, including performance of central neck dissection, incidental parathyroidectomy, and hyperthyroidism, on the incidence of postoperative hypocalcemia.
  
  
  RESULTS
  The incidence of transient biochemical hypocalcemia was 24% (n = 29/121). There was no correlation between vitamin D levels and risk of postoperative hypocalcemia. On univariate analysis, performance of concomitant central compartment neck dissection revealed an increased risk of hypocalcemia (P = .06), but this finding was not significant on multivariate analysis.
  
  
  CONCLUSIONS
  Vitamin D levels do not appear to have a significant effect on the risk of postthyroidectomy hypocalcemia.
authors.affiliation: Department of Endocrinology-Head & Neck Surgery, South Infirmary Victoria University Hospital, Cork, Ireland.
authors.forename: Tomas P
authors.initials: TP
authors.lastname: Griffin
authors.affiliation: Department of Endocrinology-Head & Neck Surgery, South Infirmary Victoria University Hospital, Cork, Ireland.
authors.forename: Matthew S
authors.initials: MS
authors.lastname: Murphy
authors.affiliation: Department of Endocrinology-Head & Neck Surgery, South Infirmary Victoria University Hospital, Cork, Ireland2Department of Otolaryngology-Head & Neck Surgery, South Infirmary Victoria University Hospital, Cork, Ireland.
authors.forename: Patrick
authors.initials: P
authors.lastname: Sheahan
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D005260:Female; D006801:Humans; D006996:Hypocalcemia / Q000453:epidemiology / Q000209:etiology*; D015994:Incidence; D008297:Male; D008875:Middle Aged; D011183:Postoperative Complications / Q000453:epidemiology / Q000209:etiology*; D012189:Retrospective Studies; D012306:Risk; D013965:Thyroidectomy; D014808:Vitamin D Deficiency / Q000453:epidemiology / Q000209:etiology*