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Completed

NCT Number: NCT02092376

The Link Between Obesity And Vitamin D in Bariatric Patients With Omega-loop Bypass Surgery

The aim of the study is to increase vitamin D concentrations or to keep it on high level, respectively, by supplementing with vitamin D3 in a different dose regime, and to improve the overall health status in bariatric patients. In this project, the vitamin D status, the parameters of inflammation, bone turnover, insulin resistance, liver and depression score of bariatric patients are expected to improve, due to supplementation of a loading dose compared to the standard therapy.

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Key information

Conditions

Bariatric Surgery Candidate

Age range

18 year–100 year

Sex eligibility

All sexes

Study type

Interventional

Phase

Phase 4

Primary location

Medical University of Vienna

Vienna, State of Vienna, 1090, Austria

Who can participate

Healthy volunteers accepted: No

Only the study team can determine whether someone qualifies for participation.

Inclusion criteria

  • Planned omega loop bypass surgery
  • 25-hydroxy vitamin D < 75 nmol/l
  • BMI >40 or ≥35 kg/m2 with co-morbidities e.g. diabetes mellitus, hypertension
  • Body weight <140 kg (due to limitation of DEXA measurement)
  • Capability to consent

Exclusion criteria

  • Another planned form of bariatric surgery
  • Hypercalcemia (calcium >2.63 mmol/l) or hypocalcemia (<1.75 mmol/l)
  • Renal insufficiency (creatinine >133 μmol/l or GFR <50 ml/min)
  • Primary hyperparathyroidism
  • Malignancy
  • Infection e.g. human immunodeficiency virus
  • Medical conditions requiring daily calcium supplements or antacid use
  • Known hypersensitivity to cholecalciferol
  • No capability to consent
  • Imprisoned persons

Treatment and study plan

Cholecalciferol

Drug

Placebo

Drug

Primary outcomes

  1. 25-hydroxy vitamin D levels

    Time frame: 24 weeks postoperatively

    25-hydroxy vitamin D levels after 24 weeks measured in intervention and placebo group, adjusting for the baseline value as covariate

Secondary outcomes

  1. Prevalence of sufficient vitamin D

    Time frame: 24 weeks postoperatively

    Number of patients reaching 25-hydroxyvitamin D levels above 75 nmol/l

  2. Prevalence of vitamin D deficiency

    Time frame: 24 weeks postoperatively

    Prevalence of vitamin D deficiency

  3. Co-morbidities

    Time frame: 24 weeks postoperatively

    Prevalence of Co-morbidities

  4. Prescribed medication

    Time frame: 24 weeks postoperatively

    Change in prescribed medication

  5. Body weight, body composition

    Time frame: 24 weeks postoperatively

    Change in body weight and body composition by bioelectrical impedance analysis

  6. Blood pressure

    Time frame: 24 weeks postoperatively

    Change of vital signs (blood pressure)

  7. Laboratory parameters

    Time frame: 24 weeks postoperatively

    Change in laboratory parameters compared to baseline: vitamin D status, bone turnover markers, calcium homeostasis, parathyroid hormone, inflammation, insulin resistance

  8. Depression symptoms

    Time frame: 24 weeks postoperatively

    Prevalence of depression symptoms assessed by Beck Depression Inventory Questionnaire

  9. Bone mineral density and body fat content

    Time frame: 24 weeks postoperatively

    Assessment of bone mineral density and total body fat content by DEXA

  10. Liver condition

    Time frame: 24 weeks postoperatively

    Measurement of liver stiffness and fat content by FibroScan and CAP

  11. Dietary assessment

    Time frame: 24 weeks postoperatively

    Dietary assessment will be documented with a 5-day food record to calculate vitamin D intake and the Mediterranean Score (questionnaire with calculated score)

  12. Gut microbiota composition

    Time frame: 24 weeks postoperatively

    Association between vitamin D, gut microbiota and surgery-induced weight loss, by collecting stool samples

  13. Vitamin D in adipose and liver tissue

    Time frame: during surgery

    For instance, for the purposes of describing adipose depot vitamin D concentrations and expression of enzymes in subcutaneous, visceral adipose and liver tissue samples will be collected during the omega loop gastric bypass surgery. Furthermore, the liver tissue samples should be used in addition for a histological examination as extended diagnostics (NAFLD/ NASH).

Sponsors and collaborators

Lead sponsor

Maria Luger

Other

Registry information

Official study title

The Link Between Obesity And Vitamin D in Bariatric Patients With Omega-loop Bypass Surgery: a Randomized Controlled, Double-blinded Clinical Supplementation Trial

Acronym: LOAD

Important dates

Study start
2014
Primary completion
2015
Study completion
2016
First posted
Mar 20, 2014
Registry last updated
Jul 14, 2016

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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