Vitamin D Deficiency and Postoperative Hypocalcemia

Study Overview
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Brief Summary
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Hypocalcemia is a frequent adverse event after thyroidectomy. It is usually related to hypoparathyroidism, but preoperative hypocalcemia, hypomagnesemia or vitamin D deficiency contributes to it. This study aims to determine the frequency of vitamin D deficiency or insufficiency in patients submitted to thyroidectomy, to define the risk attributed to vitamin D deficiency to postoperative hypocalcemia, to identify other factors associated to postoperative calcium disorder, and to evaluate the benefit of preoperative treatment of vitamin D deficiency to prevent postoperative hypocalcemia.

Detailed Description
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Subjects to be submitted to total thyroidectomy will be included in the study. The investigators will evaluate serum levels of total calcium, ionic calcium, phosphorus, magnesium, creatinine, albumin, alkaline phosphatase, fasting glucose, thyroid stimulating hormone (TSH), free thyroxin (FT4), intact parathyroid hormone (PTH), 25 hydroxy vitamin D (25OHD), osteocalcin, C-terminal telopeptide (CTX) and procollagen type 1 amino-terminal propeptide (P1NP). Patients will be randomized to 3 groups: (1) 30 subjects with 25OHD < 20 ng/mL that will receive 100,000U of cholecalciferol weekly for 4 weeks before surgery, (2) 30 subjects with 25OHD < 20 ng/mL that will not receive cholecalciferol before surgery and (3) 30 controls with 25OHD >= 20 ng/mL that will not receive cholecalciferol before surgery. Afterwards, the investigators will evaluate immediate postoperative PTH and measure serum levels of total calcium, ionic calcium, magnesium, alkaline phosphatase, osteocalcin, CTX and P1NP in first and second postoperative days for further analysis.

Official Title
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Correction of Vitamin D Deficiency to Prevent Postoperative Hypocalcemia After Thyroidectomy

Conditions
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Hypocalcemia

Intervention / Treatment
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* Drug: Cholecalciferol


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: patients that will be submitted to total thyroidectomy Exclusion Criteria: < 18 year-old chronic renal failure (creatinine > 1.5 mg/dL) fasting glucose > 200 mg/dl albumin < 3.5 g/L preoperative use of calcium supplements, bisphosphonates, corticosteroids

Ages Eligible for Study
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Minimum Age: 18 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Prevention
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Active Comparator: Vitamin D deficiency treatment<br>subjects with 25OHD < 20 ng/mL that will receive 100,000U of cholecalciferol weekly for 4 weeks before surgery | Drug: Cholecalciferol<br>* 100,000 U of cholecalciferol weekly for 4 weeks<br>|
| No Intervention: Vitamin D deficiency observation<br>subjects with 25OHD < 20 ng/mL that will not receive cholecalciferol before surgery | |
| No Intervention: Vitamin D sufficiency<br>controls with 25OHD >= 20 ng/mL that will not receive cholecalciferol before surgery | |

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| postoperative hypocalcemia |  | up to 2 days | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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hypocalcemia, vitamin D deficiency, cholecalciferol, thyroidectomy