Vitamin D Deficiency in Adolescent Girls
|Healthy Vitamin D Deficiency||Dietary Supplement: ergocalciferol Other: placebo pill|
|Study Design:||Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Double Blind (Participant, Care Provider, Investigator, Outcomes Assessor)
Primary Purpose: Basic Science
|Official Title:||Vitamin D Deficiency in Adolescent Girls|
- change in FGF23 level with vitamin D repletion [ Time Frame: baseline and 16 weeks ]
- change in bone turnover markers with vitamin D repletion [ Time Frame: baseline and 16 weeks ]
- change in mineral metabolism factors with vitamin D repletion [ Time Frame: baseline and 16 weeks ]
- change in insulin sensitivity with vitamin D repletion [ Time Frame: baseline and 16 weeks ]
|Study Start Date:||September 2010|
|Study Completion Date:||April 2013|
|Primary Completion Date:||April 2013 (Final data collection date for primary outcome measure)|
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 Name: 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
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.
Please refer to this study by its ClinicalTrials.gov identifier: NCT01180946
|United States, Massachusetts|
|Massachusetts General Hospital|
|Boston, Massachusetts, United States, 02114|
|Principal Investigator:||Sherri-Ann Burnett-Bowie, MD, MPH||Massachusetts General Hospital|