How Does Magnesium Status Influence Calcium Homeostasis?

This study is ongoing, but not recruiting participants.
Sponsor:
Collaborators:
Information provided by (Responsible Party):
University of Wisconsin, Madison
ClinicalTrials.gov Identifier:
NCT01593501
First received: May 4, 2012
Last updated: June 16, 2014
Last verified: June 2014

May 4, 2012
June 16, 2014
May 2012
September 2014   (final data collection date for primary outcome measure)
Evaluate the associations between magnesium intake, magnesium stores, fractional magnesium absorption and calcium homeostasis. [ Time Frame: 0-12 months ] [ Designated as safety issue: No ]
To evaluate relationships between magnesium intake and fractional magnesium absorption at baseline and 12 months, among 60 women participating in HSC Protocol 2009-0055, and to assess whether vitamin D therapy influences magnesium absorption among these women. We will also evaluate whether data collected from less than 72 hours of urine following tracer administration permits accurate assessment of fractional magnesium absorption.
Same as current
Complete list of historical versions of study NCT01593501 on ClinicalTrials.gov Archive Site
  • Does vitamin D therapy have a differential impact on calcium absorption that is dependent on magnesium stores? [ Time Frame: 0-12 months ] [ Designated as safety issue: No ]
    To assess whether vitamin D therapy has a differential impact on calcium absorption, depending on magnesium stores. We will use data from all subjects participating in HSC Protocol 2009-0055 to evaluate whether magnesium status is a co-factor in the change in calcium absorption that occurs with vitamin D therapy.
  • Assessing relationships between magnesium status and bone mineral density. [ Time Frame: 0-12 months ] [ Designated as safety issue: No ]
  • Evaluate how magnesium status impacts the relationship between vitamin D levels and parathyroid hormone levels. [ Time Frame: 0-12 months ] [ Designated as safety issue: No ]
Same as current
Not Provided
Not Provided
 
How Does Magnesium Status Influence Calcium Homeostasis?
How Does Magnesium Status Influence Calcium Homeostasis?

The investigators aim to recruit 60 women who have agreed to participate in an existing randomized, double-blind, placebo-controlled trial (Treatment of Vitamin D Insufficiency, HSC 2009-0055). In this trial, the investigators propose to evaluate the associations between magnesium intake, magnesium stores, fractional magnesium absorption and calcium homeostasis. The investigators will stratify 60 subjects in the sub-study, ensuring that approximately 20 subjects are randomized into each treatment arm (placebo, low-dose and high-dose vitamin D). The investigators already assess calcium homeostasis throughout the study by measuring bone mineral density, fractional calcium absorption, serum and urine calcium levels, among other tests. In the sub-study of 60 women, the investigators will evaluate whether habitually higher magnesium intake increases or decreases fractional calcium absorption. The investigators will evaluate the interplay between magnesium stores, vitamin D levels and serum parathyroid hormone levels. The investigators will directly assess magnesium stores using serum magnesium and 24-hour urine magnesium levels, and will measure magnesium absorption using the dual stable isotope approach.

Use of serum magnesium isotopes to measure fractional magnesium absorption Four day food diaries to assess magnesium intake Standard urine and serum chemistries for remaining labs as noted above

Interventional
Phase 4
Allocation: Randomized
Endpoint Classification: Efficacy Study
Intervention Model: Parallel Assignment
Masking: Double Blind (Subject, Investigator)
Primary Purpose: Treatment
  • Magnesium Deficiency
  • Calcium Metabolism Disorders
Dietary Supplement: vitamin D3
pharmaceutical grade D3
Other Name: Cholecalciferol
  • Active Comparator: High dose vitamin D
    50,000 IU vitamin D3 every 15 days, with a loading dose of 50,000 IU per day for the first 15 days of an approximate 365-day treatment.
    Intervention: Dietary Supplement: vitamin D3
  • Active Comparator: Low dose vitamin D
    800 IU vitamin D3 every day of an approximate 365-day treatment.
    Intervention: Dietary Supplement: vitamin D3
  • Placebo Comparator: Placebo
    A pill that looks like the low/high dose vitamin D pills, but contains no vitamin D. Given to preserve the double-blind nature of the study.
    Intervention: Dietary Supplement: vitamin D3
Hansen KE, Nabak AC, Johnson RE, Marvdashti S, Keuler NS, Shafer MM, Abrams SA. Isotope concentrations from 24-h urine and 3-h serum samples can be used to measure intestinal magnesium absorption in postmenopausal women. J Nutr. 2014 Apr;144(4):533-7. doi: 10.3945/jn.113.186767. Epub 2014 Feb 5.

*   Includes publications given by the data provider as well as publications identified by ClinicalTrials.gov Identifier (NCT Number) in Medline.
 
Active, not recruiting
60
September 2014
September 2014   (final data collection date for primary outcome measure)

Inclusion Criteria:

  • participants eligible for the study "Treatment of vitamin D insufficiency" are eligible for participation in the current sub-study

Exclusion Criteria:

  • identical to those covered in HSC #2009-0055
Female
30 Years to 75 Years
Yes
Contact information is only displayed when the study is recruiting subjects
United States
 
NCT01593501
HSC #2011-0547, R01AG028739-01A2
Yes
University of Wisconsin, Madison
University of Wisconsin, Madison
  • National Institutes of Health (NIH)
  • National Institute on Aging (NIA)
Principal Investigator: Karen E Hansen, M.D., M.S. University of Wisconsin-Madison, Department of Medicine, Division of Rheumatology
University of Wisconsin, Madison
June 2014

ICMJE     Data element required by the International Committee of Medical Journal Editors and the World Health Organization ICTRP