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Vitamin D AND Glucose Handling Evaluated by Glucose Clamp (D-clamp)

This study has been completed.
Norwegian Council on Cardiovascular diseases
Information provided by (Responsible Party):
University Hospital of North Norway Identifier:
First received: December 16, 2008
Last updated: November 2, 2011
Last verified: November 2011

In this study the investigators want to compare glucose handling (insulin secretion and insulin sensitivity) in 100 persons with low and 50 persons with normal-high levels of vitamin D, using a hyperglycemic clamp technique, were sugar is given intravenously for 3 hours in order to keep the blood sugar level at 10 mmol/L. Those with low vitamin D levels will be randomized to treatment with vitamin D3 (cholecalciferol) 40 000 IU/week or placebo for 6 months before a new clamp is performed.

The study hypothesis is that persons with low vitamin D levels have impaired glucose handling which might be improved by vitamin D supplementation.

Condition Intervention Phase
Insulin Sensitivity Intraocular Pressure Drug: cholecalciferol Phase 2

Study Type: Interventional
Study Design: Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Quadruple (Participant, Care Provider, Investigator, Outcomes Assessor)
Primary Purpose: Basic Science
Official Title: Vitamin D AND Cardiovascular Disease

Resource links provided by NLM:

Further study details as provided by University Hospital of North Norway:

Primary Outcome Measures:
  • insulin secretion and sensitivity as assessed by an hyperglycemic clamp [ Time Frame: 6 months ]
  • intraocular pressure [ Time Frame: 6 months ]

Secondary Outcome Measures:
  • telomer length [ Time Frame: 6 months ]
  • 25-hydroxyvitamin D and 1,25-dihydroxyvitamin D-levels [ Time Frame: 6 months ]
  • serum calcium, PTH, phosphate [ Time Frame: 6 months ]
  • inflammatory markers and lipids [ Time Frame: 6 months ]

Enrollment: 160
Study Start Date: November 2008
Study Completion Date: December 2010
Primary Completion Date: December 2010 (Final data collection date for primary outcome measure)
Intervention Details:
    Drug: cholecalciferol
    capsules, 20 000IU, twice a week, 6 months duration

Ages Eligible for Study:   30 Years to 75 Years   (Adult, Senior)
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   No

Inclusion Criteria:

  • generally: Subjects are recruited from the 6th Tromsø Study
  • cases: serum 25-hydroxyvitamin D-levels below the 10 percentile; low levels confirmed with new serum analyses.
  • controls: serum 25-hydroxyvitamin D levels 80-95 percentile, normal-high levels confirmed with new serum analyses.

Exclusion Criteria:

  • diabetes
  • myocardial infarction or apoplexia
  • active cancer during last 5 years
  • history of kidney stone
  • pregnancy or premenopausal without safe anticonception
  • primary hyperparathyroidism
  • systolic blood pressure >175 or diastolic blood pressure >105
  Contacts and Locations
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Please refer to this study by its identifier: NCT00809744

University Hospital of North Norway
Tromsø, Norway, 9037
Sponsors and Collaborators
University Hospital of North Norway
Norwegian Council on Cardiovascular diseases
Principal Investigator: Rolf Jorde, Professor Medical Dpt, University Hospital of Northern Norway
  More Information

Publications automatically indexed to this study by Identifier (NCT Number):
Responsible Party: University Hospital of North Norway Identifier: NCT00809744     History of Changes
Other Study ID Numbers: UIT-ENDO-2008-GURI-2
Study First Received: December 16, 2008
Last Updated: November 2, 2011

Additional relevant MeSH terms:
Insulin Resistance
Glucose Metabolism Disorders
Metabolic Diseases
Vitamin D
Growth Substances
Physiological Effects of Drugs
Bone Density Conservation Agents processed this record on September 21, 2017