Vitamin D Deficiency in Adolescent Girls

November 1, 2013 updated by: Sherri-Ann M. Burnett-Bowie, Massachusetts General Hospital
Fibroblast growth factor 23 (FGF23) is a newly discovered hormone which regulates phosphate and vitamin D levels. In this study, we are looking at what the normal levels of FGF23 are in adolescent girls and how these levels vary with other hormonal measurements. We will also be looking at whether vitamin D supplementation in adolescents who are deficient in vitamin D alters the levels of FGF23 and other factors including insulin resistance.

Study Overview

Status

Completed

Conditions

Intervention / Treatment

Detailed Description

Fibroblast growth factor 23 (FGF23) is a newly discovered hormone. Its primary function is to regulate phosphate metabolism, which it does both by directly regulating phosphate excretion through the kidney as well as by regulating vitamin D activity. What controls FGF23 levels is still under investigation; potential factors include dietary phosphate intake and vitamin D levels.

In this pilot study, we aim to investigate what the normal levels of FGF23 are in healthy girls and how these are related to other measurements of bone and mineral metabolism. Since vitamin D deficiency is very common in healthy girls, we expect a subset of the subjects in this study to be vitamin D deficient. We will then randomize these girls to vitamin D repletion or placebo and follow changes in FGF23 levels. Vitamin D deficiency has also been implicated in insulin resistance which is a precursor to diabetes. We will therefore also look at changes in insulin resistance with vitamin D repletion.

Study Type

Interventional

Enrollment (Actual)

90

Phase

  • Not Applicable

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Locations

  • United States
    • Massachusetts
      • Boston, Massachusetts, United States, 02114
        • Massachusetts General Hospital

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

9 years to 18 years (Child, Adult)

Accepts Healthy Volunteers

Yes

Genders Eligible for Study

Female

Description

Inclusion Criteria:

  • healthy girls aged 9-18 years

Exclusion Criteria:

  • significant cardiac, hepatic, oncologic, or psychiatric disease
  • a history of malabsorption, kidney stones, hypoparathyroidism, or growth hormone deficiency
  • pregnancy
  • diabetes mellitus
  • BMI>/= 99th percentile for age and sex
  • fracture within the preceding 3 months
  • hypogonadism (no pubertal development by age 12, absence of menarche by age 14)
  • serum calcium <8 mg/dl or >11 mg/dl
  • radiographic evidence of rickets
  • use of medications know 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 D (>20,000 units/day), calcitriol, growth hormone, or anti-convulsants.
  • use of hormonal birth control

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Basic Science
  • Allocation: Randomized
  • Interventional Model: Parallel Assignment
  • Masking: Quadruple

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Active Comparator: Ergocalciferol
Weekly ergocalciferol for 16 weeks
Dietary supplement: ergocalciferol
ergocalciferol (a dietary form of vitamin D). 50,000 units by mouth once a week for 16 weeks.
Other Names:
  • vitamin D
Placebo Comparator: Placebo
Placebo pill. Note that all subjects in this arm will receive vitamin D repletion at the conclusion of the study.
Other: placebo pill
placebo pill once weekly for 16 weeks. At the end of the study, subjects in this arm will receive vitamin D repletion

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Time Frame
change in FGF23 level with vitamin D repletion
Time Frame: baseline and 16 weeks
baseline and 16 weeks

Secondary Outcome Measures

Outcome Measure
Time Frame
change in bone turnover markers with vitamin D repletion
Time Frame: baseline and 16 weeks
baseline and 16 weeks
change in mineral metabolism factors with vitamin D repletion
Time Frame: baseline and 16 weeks
baseline and 16 weeks
change in insulin sensitivity with vitamin D repletion
Time Frame: baseline and 16 weeks
baseline and 16 weeks

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Massachusetts General Hospital

Investigators

  • Principal Investigator: Sherri-Ann Burnett-Bowie, MD, MPH, Massachusetts General Hospital

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

General Publications

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start

September 1, 2010

Primary Completion (Actual)

April 1, 2013

Study Completion (Actual)

April 1, 2013

Study Registration Dates

First Submitted

August 11, 2010

First Submitted That Met QC Criteria

August 11, 2010

First Posted (Estimate)

August 12, 2010

Study Record Updates

Last Update Posted (Estimate)

November 5, 2013

Last Update Submitted That Met QC Criteria

November 1, 2013

Last Verified

November 1, 2013

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

  • 2010-P-001126/1

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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