Duration of Vitamin D Stores After Prolonged Vitamin D Substitution

NCT01729013 | Completed

• 1 other identifier: Tromsø-Endo-2012-2
• Study Type: observational
• Target: 78
• Locations: 1 country
• Sites: 1

Brief 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. 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

Outcome Measures

Primary Outcomes (1)

• half-life of serum 25-hydroxyvitamin D

  up to 12 months

Study Arms (2)

subjects previously given placebo

subjects previously given vitamin D

Eligibility Criteria

• Age: 25 Years - 85 Years
• Sex: all
• Healthy Volunteers: Yes
• Age Groups: Adult (18-64), Older Adult (65+)
• Sampling Method: Non-Probability Sample

Study Population

Subjects who have previously participated in a vitamin D study

You may qualify if:

• previously participated in a vitamin D study

You may not qualify if:

• pregnancy

Sponsors & Collaborators

• University of Tromso: lead

Study Sites (1)

University of Tromsø

Tromsø, Tromsø, 9037, Norway

Location

Related Publications (1)

• 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.

  PMID: 28973683 DERIVED

Biospecimen

Retention: SAMPLES WITHOUT DNA

blood samples and fat biopsy

MeSH Terms

Conditions

Obesity; Platelet Glycoprotein IV Deficiency

Condition Hierarchy (Ancestors)

Overweight; Overnutrition; Nutrition Disorders; Nutritional and Metabolic Diseases; Body Weight; Signs and Symptoms; Pathological Conditions, Signs and Symptoms

Study Officials

• rolf jorde, professor

  University of Tromso

  PRINCIPAL INVESTIGATOR

Study Design

• Study Type: observational
• Observational Model: COHORT
• Time Perspective: PROSPECTIVE
• Sponsor Type: OTHER
• Responsible Party: SPONSOR

Study Record Dates

• First Submitted: November 13, 2012
• First Posted: November 20, 2012
• Study Start: November 1, 2012
• Primary Completion: May 1, 2015
• Study Completion: August 1, 2015
• Last Updated: September 22, 2015

Record last verified: 2015-09

Locations

NO (1)