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Vitamin D DeficiencyNCT00491322

Vitamin D Deficiency, Insulin Resistance and FGF-23

A study testing Ergocalciferol in people with Vitamin D Deficiency, run by Massachusetts General Hospital at 1 site in United States.

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

The purpose of this project is to determine if treating vitamin D deficiency decreases insulin resistance and improves insulin secretion in healthy volunteers. Additionally, this project will investigate if treating vitamin D deficiency affects a new phosphate-regulating hormone called FGF-23. Read more about this study

Who is it for?
Ages 18 to 45 yearsHealthy volunteers can take part
Conditions the study is for
Vitamin D Deficiency
What is being tested?
Ergocalciferol
Could I receive a placebo?
Yes, some participants may receive a placebo
How many people
92 participants
Where
1 siteUnited States
Study dates
May 2006to Feb 2008
Phase
Interventional
Are there results?
Yes, posted in the registrySummary in the doctors' view

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 18 to 45 years
  • All sexes
  • Healthy volunteers accepted
  • Adult

Who may be able to join

  • Age 18 to 45 yrs
  • Serum 25-OHD < or = 20 ng/mL
  • At least 1 menses in the last 3 months (females) and normal serum testosterone (males)

Who cannot join

  • Significant cardiac, hepatic, oncologic, or psychiatric disease
  • History of diabetes mellitus, malabsorption, kidney stones, or recent alcohol excess/abuse (15 drinks per week in the last month)
  • Fasting glucose > 126 mg/dl or 2 hour OGTT > 200 mg/dl
  • Use of medications known to affect serum phosphate levels including phosphate-binding antacids, sodium etidronate, calcitonin, excessive doses of vitamin D (> 1000 units per day), excessive doses of vitamin A (> 20,000 units/day), calcitriol, growth hormone, or anti-convulsants
  • Use of metformin or insulin sensitizing agents
  • Serum calcium < 8 or > 11 mg/dL, creatinine > 1.5 mg/dL, or Hgb < 11 gm/dL
Show all 12Show fewer
  • Liver function tests > 2 times the upper limit of normal
  • TSH < 0.1 or > 7 uU/mL
  • WBC < 2,000 or > 15,000/cmm
  • Platelet count < 100,000 or > 500,000/cum
  • Hormone replacement therapy or testosterone use
  • Urine uhCG positive (females), testosterone < 270 ng/dL (males)

Trial locations and contacts

1 site in 1 country.

United States1 site
  • Massachusetts General Hospital

    Boston, Massachusetts, 02114

Other trials in United States

About this study

Official title: Impact of Vitamin D Deficiency on Insulin Resistance and the Regulation of FGF-23

The purpose of this project is to determine if treating vitamin D deficiency decreases insulin resistance and improves insulin secretion in healthy volunteers. Additionally, this project will investigate if treating vitamin D deficiency affects a new phosphate-regulating hormone called FGF-23.

Read the detailed description

Vitamin D deficiency or hypovitaminosis D, defined as serum 25 hydroxyvitamin D < or = 20 ng/mL, is prevalent in several populations in the United States, specifically minorities and the elderly. Causes of vitamin D deficiency include lack of exposure to sunlight, malnutrition, and drugs that alter vitamin D metabolism and absorption.

Vitamin D is an essential factor for many organ systems. Data suggest that vitamin D is required for normal insulin secretion by the pancreas. Specifically, animal studies demonstrate that treatment of vitamin D deficiency improves insulin secretion. In humans, there is less consensus about the impact of vitamin D deficiency on insulin resistance. In one study of middle-aged patients with Type 2 diabetes mellitus, no association was seen between serum 25 hydroxyvitamin D levels and a measure of insulin resistance. However, in a larger study of younger glucose tolerant subjects, serum 25 hydroxyvitamin D levels were associated with both insulin secretion and insulin resistance. These data suggest that treatment of vitamin D deficiency may delay or prevent the development of insulin resistance, and thus diabetes mellitus type 2. Repletion of this common vitamin deficiency could therefore have major public health implications for the prevention of diabetes mellitus.

Fibroblast growth factor 23 (FGF-23) is a newly discovered phosphaturic hormone that is regulated by both dietary and serum phosphate. Hormonal regulation of FGF-23, however, is largely unknown. Recent data suggest that vitamin D plays an important role in the regulation of FGF-23. Some groups have shown that inactivation of the vitamin D receptor gene decreases serum FGF-23 levels in mice; administration of 1,25 dihydroxyvitamin D stimulates the transcription of the FGF-23 gene in vitro. Little is known, however, about the regulation of FGF-23 by vitamin D in humans.

Phosphate is critical for bone mineralization, muscle function, signal transduction, and the creation and utilization of energy. Vitamin D deficiency can result in phosphate malabsorption, osteomalacia and increased risk of fractures. Enhanced understanding of the regulation of this new phosphate-regulating hormone, FGF-23, will advance the field of phosphate metabolism.

Being tested
Ergocalciferol, Ergocalciferol placebo
Keywords
Vitamin D, Vitamin D deficiency, Insulin resistance, Diabetes, Diabetes mellitus, FGF-23, FGF23, Phosphate
Medical subject headings
Vitamin D Deficiency, Insulin Resistance, Diabetes Mellitus

What participants receive

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

  • ErgocalciferolDietary supplement

    Ergocalciferol 50000 international units once a week for 12 weeks

  • Ergocalciferol placeboDietary supplement

    Ergocalciferol placebo once a week for 12 weeks

Study groups in NCT00491322
Study groupRoleWhat they receive
Ergocalciferol groupExperimentalErgocalciferol 50000 international units once a week for 12 weeks
Receives: Dietary Supplement: Ergocalciferol
Ergocalciferol Placebo groupPlacebo comparatorMatching placebo once a week for 12 weeks
Receives: Dietary Supplement: Ergocalciferol placebo

What is being measured

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

  1. Fibroblast Growth Factor 23 (FGF23) After 12 Weeks of Weekly Ergocalciferol 50000 Units

    Fibroblast growth factor 23 (FGF23) is a phosphate and vitamin D regulating hormone.

    Measured: 12 weeks

Timeline

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

  1. First posted26 Jun 2007 (estimated)
  2. Study startMay 2006
  3. Primary completionFeb 2008
  4. Study completionFeb 2008

Resources

More details

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

Study design
Study type
Interventional
Phase
Phase N/A
Primary purpose
Treatment
Allocation
Randomised
Intervention model
Parallel groups
Masking
Triple blind
Who is masked
Participant, Care provider, Investigator
Enrolment
92 participants (actual)
IDs, dates and publications
ClinicalTrials.gov ID
NCT00491322
Sponsor's protocol ID
2006-P-000430/18
Other IDs
K23DK073356
Status last verified
Apr 2018
First submitted
22 Jun 2007
Last updated
2 May 2018
Data monitoring committee
Yes
FDA-regulated drug
No
FDA-regulated device
No
Individual data sharing
No

Publications

  • Burnett SM, Gunawardene SC, Bringhurst FR, Juppner H, Lee H, Finkelstein JS. Regulation of C-terminal and intact FGF-23 by dietary phosphate in men and women. J Bone Miner Res. 2006 Aug;21(8):1187-96. doi: 10.1359/jbmr.060507.

    PubMed 16869716
  • Burnett-Bowie SM, Mendoza N, Leder BZ. Effects of gonadal steroid withdrawal on serum phosphate and FGF-23 levels in men. Bone. 2007 Apr;40(4):913-8. doi: 10.1016/j.bone.2006.10.016. Epub 2006 Dec 8.

    PubMed 17157573
  • Burnett-Bowie SA, Leder BZ, Henao MP, Baldwin CM, Hayden DL, Finkelstein JS. Randomized trial assessing the effects of ergocalciferol administration on circulating FGF23. Clin J Am Soc Nephrol. 2012 Apr;7(4):624-31. doi: 10.2215/CJN.10030911. Epub 2012 Feb 2.

    PubMed 22300739
  • Mitchell DM, Leder BZ, Cagliero E, Mendoza N, Henao MP, Hayden DL, Finkelstein JS, Burnett-Bowie SA. Insulin secretion and sensitivity in healthy adults with low vitamin D are not affected by high-dose ergocalciferol administration: a randomized controlled trial. Am J Clin Nutr. 2015 Aug;102(2):385-92. doi: 10.3945/ajcn.115.111682. Epub 2015 Jul 8.

    PubMed 26156733

Questions about this trial

What is this clinical trial studying?

A study testing Ergocalciferol in people with Vitamin D Deficiency, run by Massachusetts General Hospital at 1 site in United States.

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 3 inclusion and 12 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 2 May 2018. 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 United States. 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. Some participants in this study may receive a placebo. 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?

Yes. Results are posted in the registry (first posted 2 May 2018). A summary is in the For doctors view, and the full results are on ClinicalTrials.gov.

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?

Fibroblast Growth Factor 23 (FGF23) After 12 Weeks of Weekly Ergocalciferol 50000 Units (time frame: 12 weeks). 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 NCT00491322, which also lists 4 linked publications.

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 2 May 2018.

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