Vitamin D for the Prevention of Diabetes Type 2

This study has been completed.
University Hospital of North Norway
Information provided by (Responsible Party):
University of Tromso Identifier:
First received: May 9, 2008
Last updated: September 18, 2015
Last verified: September 2015
The prevalence of type 2 diabetes is increasing, which for most societies has considerable consequences not only regarding health but also economy. Type 2 diabetes develops through a "prediabetic" stage with impaired glucose tolerance. Intervention at this stage with change in lifestyle or with medication may prevent such progression. There are indications that vitamin D is of importance in glucose metabolism, and that supplementation with vitamin D may increase both insulin secretion and insulin sensitivity. Accordingly, supplementation with vitamin D may improve glucose tolerance and potentially prevent the development of type 2 diabetes in subjects at risk. However, this has so far not been demonstrated in a prospective, randomised clinical study. In the present study we will therefore include 600 subjects with impaired glucose tolerance (or impaired fasting glucose) detected in the Tromso study 2007/2008 and randomize to supplementation with vitamin D 20.000IU per week or placebo for 5 years. A glucose tolerance test will be performed each year, and development of type 2 diabetes will be the main endpoint.

Condition Intervention Phase
Impaired Glucose Tolerance
Drug: cholecalciferol
Drug: Placebo
Phase 2
Phase 3

Study Type: Interventional
Study Design: Allocation: Randomized
Endpoint Classification: Efficacy Study
Intervention Model: Parallel Assignment
Masking: Double Blind (Subject, Caregiver, Investigator)
Primary Purpose: Prevention
Official Title: Prevention of Type 2 Diabetes With Vitamin D Supplementation in Subjects With Reduced Glucose Tolerance Detected in the Tromso Study 2007/2008

Resource links provided by NLM:

Further study details as provided by University of Tromso:

Primary Outcome Measures:
  • development of diabetes type 2 [ Time Frame: 5 years ] [ Designated as safety issue: No ]

Secondary Outcome Measures:
  • change in glucose metabolism [ Time Frame: 5 years ] [ Designated as safety issue: No ]
  • change in lipid status [ Time Frame: 5 years ] [ Designated as safety issue: No ]
  • change in mood [ Time Frame: 5 years ] [ Designated as safety issue: No ]
  • change in BMD hip [ Time Frame: 5 years ] [ Designated as safety issue: No ]
  • change in intima media thickness carotid artery [ Time Frame: 5 years ] [ Designated as safety issue: No ]
  • change in frequency of infections [ Time Frame: 5 years ] [ Designated as safety issue: No ]
  • change in blood pressure [ Time Frame: 5 years ] [ Designated as safety issue: No ]
  • Change in Insulin sensitivity [ Time Frame: 5 years ] [ Designated as safety issue: No ]
  • change in HbA1c [ Time Frame: 5 years ] [ Designated as safety issue: No ]
  • change in weight [ Time Frame: 5 years ] [ Designated as safety issue: No ]
  • change in telomer length [ Time Frame: 5 years ] [ Designated as safety issue: No ]

Other Outcome Measures:
  • Oral glucose tolerance response to vitamin D supplementation in relation to polymorphisms in the vitamin D system [ Time Frame: 1 year ] [ Designated as safety issue: No ]
    The response to oral glucose tolerance test (fasting and 2 h blood glucose, serum insulin, C-peptide, measures of insulin resistiance as well as metabolic parameters (lipids, blood pressure)) will be evaluated in the results at the 1-year visit in relation to genetic polymorphisms in the vitamin D system

Enrollment: 511
Study Start Date: March 2008
Study Completion Date: September 2015
Primary Completion Date: March 2015 (Final data collection date for primary outcome measure)
Arms Assigned Interventions
Experimental: 1
Cholecalciferol 20.000 IU per week for 5 years
Drug: cholecalciferol
20.000 IU cholecalciferol per week for 5 years versus placebo
Other Name: vitamin D
Placebo Comparator: 2 Drug: Placebo
Placebo capsule once a week, identical to cholecalciferol capsule


Ages Eligible for Study:   21 Years to 80 Years
Genders Eligible for Study:   Both
Accepts Healthy Volunteers:   Yes

Inclusion Criteria:

  • Impaired glucose tolerance

Exclusion Criteria:

  • Serious heart disease
  • Renal stone disease
  • Hypercalcemia
  • Sarcoidosis
  Contacts and Locations
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Please refer to this study by its identifier: NCT00685594

University of Tromso
Tromso, Norway, 9037
Sponsors and Collaborators
University of Tromso
University Hospital of North Norway
Principal Investigator: Rolf Jorde, Professor University of Tromso
  More Information

Responsible Party: University of Tromso Identifier: NCT00685594     History of Changes
Other Study ID Numbers: UIT-ENDO-2008-1  NFR 184766/V50 
Study First Received: May 9, 2008
Last Updated: September 18, 2015
Health Authority: Norway: Norwegian Medicines Agency

Keywords provided by University of Tromso:
vitamin D
glucose tolerance

Additional relevant MeSH terms:
Glucose Intolerance
Glucose Metabolism Disorders
Metabolic Diseases
Vitamin D
Bone Density Conservation Agents
Growth Substances
Physiological Effects of Drugs processed this record on May 23, 2016