Vitamin D Deficiency in Adolescent Girls

Healthy Clinical Trial

Official title:

Vitamin D Deficiency in Adolescent Girls

Clinical Trial Details — Status: Completed

Administrative data

• NCT number: NCT01180946
• Other study ID #: 2010-P-001126/1
• Status: Completed
• Phase: N/A
• First received: August 11, 2010
• Last updated: November 1, 2013
• Start date: September 2010
• Est. completion date: April 2013

Study information

• Verified date: November 2013
• Source: Massachusetts General Hospital
• Contact: n/a
• Is FDA regulated: No
• Health authority: United States: Institutional Review Board
• Study type: Interventional

Clinical Trial Summary

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.

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.

Recruitment information / eligibility

• Status: Completed
• Enrollment: 90
• Est. completion date: April 2013
• Est. primary completion date: April 2013
• Accepts healthy volunteers: Accepts Healthy Volunteers
• Gender: Female
• Age group: 9 Years to 18 Years

Eligibility

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 Design

Allocation: Randomized, Intervention Model: Parallel Assignment, Masking: Double Blind (Subject, Caregiver, Investigator, Outcomes Assessor), Primary Purpose: Basic Science

Related Conditions & MeSH terms

• Healthy
• Vitamin D Deficiency

Intervention

Dietary Supplement:
• ergocalciferol
ergocalciferol (a dietary form of vitamin D). 50,000 units by mouth once a week for 16 weeks.

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

Locations

Country	Name	City	State
United States	Massachusetts General Hospital	Boston	Massachusetts

Sponsors (1)

Lead Sponsor	Collaborator
Massachusetts General Hospital

Country where clinical trial is conducted

United States, 

References & Publications (3)

Burnett SM, Gunawardene SC, Bringhurst FR, Jüppner 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. — View Citation

Burnett-Bowie SM, Henao MP, Dere ME, Lee H, Leder BZ. Effects of hPTH(1-34) infusion on circulating serum phosphate, 1,25-dihydroxyvitamin D, and FGF23 levels in healthy men. J Bone Miner Res. 2009 Oct;24(10):1681-5. doi: 10.1359/jbmr.090406. — View Citation

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. Epub 2006 Dec 8. — View Citation

Outcome

Type	Measure	Description	Time frame	Safety issue
Primary	change in FGF23 level with vitamin D repletion		baseline and 16 weeks	No
Secondary	change in bone turnover markers with vitamin D repletion		baseline and 16 weeks	No
Secondary	change in mineral metabolism factors with vitamin D repletion		baseline and 16 weeks	Yes
Secondary	change in insulin sensitivity with vitamin D repletion		baseline and 16 weeks	No