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ObesityNCT01729013

Duration of Vitamin D Stores After Prolonged Vitamin D Substitution

An observational study of Obesity, run by University of Tromso at 1 site in Norway.

Completed

Finished. The study has ended and is not enrolling. Results may be posted on the official record.

Official record
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Trial summary

Ingested or skin produced vitamin D is either hydroxylated in the liver to 25-hydroxyvitamin D (25(OH)D), metabolized and excreted in the urine, or stored in adipose and other tissues. Read more about this study

Who is it for?
Ages 25 to 85 yearsHealthy volunteers can take part
Conditions the study is for
Obesity
How many people
78 participants
Where
1 siteNorway
Study dates
Nov 2012to Aug 2015
Phase
Observational
Are there results?
None posted in the registry

Key requirements

Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.

  • Ages 25 to 85 years
  • All sexes
  • Healthy volunteers accepted
  • Adult, Older adult

Study population: Subjects who have previously participated in a vitamin D study

Who may be able to join

  • previously participated in a vitamin D study

Who cannot join

  • pregnancy

Trial locations and contacts

1 site in 1 country.

Norway1 site
  • University of Tromsø

    Tromsø, Tromsø, 9037

Other trials in Norway

About this study

Ingested or skin produced vitamin D is either hydroxylated in the liver to 25-hydroxyvitamin D (25(OH)D), metabolized and excreted in the urine, or stored in adipose and other tissues. The capacity for vitamin D storage in adipose tissue is not known, nor the importance of such storage which may potentially be of vital importance when intake or solar exposure is limited. In the present study we will include 76 subjects who have participated in an intervention study with vitamin D (20.000 IU per week) versus placebo for the prevention of type 2 diabetes, and who have completed the study after 5 years or who have been excluded because of diagnosed type 2 diabetes or for other reasons. If vitamin D is stored to any extent in the body the subjects given 20.000 IU vitamin D per week for 2-5 years will have a considerable amount of stored vitamin D and accordingly, a slow decline in serum 25(OH)D during the following year without vitamin D substitution, which will be measured in the present study. If our hypothesis is correct, that vitamin D can be stored in significant amounts when the supply is abundant; current advice on vitamin D supplementation mainly during winter should be changed to "year around" in order to build up sufficient stores for the months without sufficient sun light.

Conditions
Obesity
Keywords
vitamin D, fat, biopsy
Medical subject headings
Obesity, Platelet Glycoprotein IV Deficiency

What participants receive

What participants receive. In a randomised study each person is assigned to one group by chance.

Study groups in NCT01729013
Study groupRoleWhat they receive
subjects previously given placeboNot described
subjects previously given vitamin DNot described

What is being measured

The primary outcome is the main question the study is designed to answer.

  1. half-life of serum 25-hydroxyvitamin D

    Measured: up to 12 months

Timeline

From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.

  1. First posted20 Nov 2012 (estimated)
  2. Study startNov 2012
  3. Primary completionMay 2015
  4. Study completionAug 2015

Resources

More details

For doctors and researchers: how the study is designed, who runs it, and its registry IDs.

Study design
Study type
Observational
Observational model
Cohort
Time perspective
Prospective
Enrolment
78 participants (actual)
IDs, dates and publications
ClinicalTrials.gov ID
NCT01729013
Sponsor's protocol ID
Tromsø-Endo-2012-2
Status last verified
Sep 2015
First submitted
13 Nov 2012
Last updated
22 Sep 2015
Results posted
No
Data monitoring committee
No

Publications

  • Martinaityte I, Kamycheva E, Didriksen A, Jakobsen J, Jorde R. Vitamin D Stored in Fat Tissue During a 5-Year Intervention Affects Serum 25-Hydroxyvitamin D Levels the Following Year. J Clin Endocrinol Metab. 2017 Oct 1;102(10):3731-3738. doi: 10.1210/jc.2017-01187.

    PubMed 28973683

Questions about this trial

What is this clinical trial studying?

An observational study of Obesity, run by University of Tromso at 1 site in Norway.

The full registered description is in the About this study section and the official record.

Who may be eligible to take part?

The sponsor lists 1 inclusion and 1 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.

Is this clinical trial currently recruiting?

The record says: finished, as of the sponsor's last update on 22 Sep 2015. Status can change between updates, so confirm with the study contact before making plans.

Where is the study taking place?

The record lists 1 site in Norway. Whether a site is taking part right now should be confirmed with that site. See every site.

What are the possible benefits and risks?

They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.

Are results available for this study?

The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.

How can a doctor refer a patient or contact the research team?

The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.

What does the primary outcome measure?

half-life of serum 25-hydroxyvitamin D (time frame: up to 12 months). It is what the study was designed to measure, not a finding.

Where can I read the original study information?

On the ClinicalTrials.gov record for NCT01729013, which also lists 1 linked publication.

Does a listing mean the treatment is approved or proven to work?

No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.

How often is this information updated?

AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 22 Sep 2015.

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