title: The role of vitamin D in post-thyroidectomy hypocalcemia: Still an enigma.
abstract: BACKGROUND
  There is conflicting evidence regarding the role of vitamin D deficiency in the development of post-thyroidectomy hypocalcemia. Recent reports show postoperative parathormone (PTH) is unreliable in predicting post-thyroidectomy hypocalcemia in vitamin D deficient patients. We conducted this study to analyze the role of vitamin D status in the development of post-thyroidectomy hypocalcemia and to evaluate its effect on the predictability of PTH as a marker for post-thyroidectomy hypocalcemia.
  
  
  METHODS
  A retrospective review of prospectively collected data of patients undergoing thyroidectomy between August 2007 to September 2013 (n = 150) was performed. Results of preoperative calcium, albumin, vitamin D, PTH and postoperative calcium, albumin, and PTH were collated. Patients were divided into 2 groups based on their vitamin D status: group A, vitamin D ≥ 20 ng/mL and group B, vitamin D < 20 ng/mL.
  
  
  RESULTS
  Vitamin D deficiency was present in 80 (53.3%) patients and post-thyroidectomy hypocalcemia developed in 67 (44.7%). The incidence of postoperative hypocalcemia was similar in both the groups (48.6% and 41.3%, respectively). Vitamin D status was not associated with the development of post-thyroidectomy hypocalcemia (P = .23). Postoperative PTH of <8 pg/mL was strongly associated with the development of hypocalcemia in both the groups (P = .0002 and .0045, respectively). The area under the receiver operator characteristic curve in group B (0.68) was less than in group A (0.76; P = .41).
  
  
  CONCLUSIONS
  The majority of patients were vitamin D deficient in this cohort, but this did not increase the risk of post-thyroidectomy hypocalcemia, nor did it interfere with the predictability of PTH as a marker of post-thyroidectomy hypocalcemia.
authors.affiliation: Department of Endocrine Surgery, Christian Medical College, Vellore, Tamil Nadu, India. Electronic address: anish@cmcvellore.ac.in.
authors.forename: Anish Jacob
authors.initials: AJ
authors.lastname: Cherian
authors.affiliation: Department of Vascular Surgery, Christian Medical College, Vellore, Tamil Nadu, India.
authors.forename: Sam
authors.initials: S
authors.lastname: Ponraj
authors.affiliation: Department of Biostatistics, Christian Medical College, Vellore, Tamil Nadu, India.
authors.forename: Mahasampath
authors.initials: M
authors.lastname: Gowri S
authors.affiliation: Department of Endocrine Surgery, Christian Medical College, Vellore, Tamil Nadu, India.
authors.forename: Pooja
authors.initials: P
authors.lastname: Ramakant
authors.affiliation: Department of Endocrinology, Christian Medical College, Vellore, Tamil Nadu, India.
authors.forename: Thomas V
authors.initials: TV
authors.lastname: Paul
authors.affiliation: Department of Endocrine Surgery, Christian Medical College, Vellore, Tamil Nadu, India.
authors.forename: Deepak Thomas
authors.initials: DT
authors.lastname: Abraham
authors.affiliation: Department of Endocrine Surgery, Christian Medical College, Vellore, Tamil Nadu, India.
authors.forename: M J
authors.initials: MJ
authors.lastname: Paul
mesh_terms: D000328:Adult; D000368:Aged; D005260:Female; D006801:Humans; D006996:Hypocalcemia / Q000175:diagnosis / Q000453:epidemiology / Q000209:etiology*; D015994:Incidence; D008297:Male; D008875:Middle Aged; D011183:Postoperative Complications / Q000175:diagnosis / Q000453:epidemiology / Q000209:etiology*; D015995:Prevalence; D012189:Retrospective Studies; D012307:Risk Factors; D013965:Thyroidectomy; D014808:Vitamin D Deficiency / Q000150:complications* / Q000175:diagnosis