How Does Magnesium Status Influence Calcium Homeostasis?

NCT01593501 | Completed Phase 4 DMC

• 2 other identifiers: HSC #2011-0547R01AG028739-01A2
• Study Type: interventional
• Target: 39
• Locations: 1 country
• Sites: 1

Brief Summary

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.

Conditions

Magnesium Deficiency; Calcium Metabolism Disorders

Keywords

vitamin D; cholecalciferol; bone mineral density; Magnesium deficiency; Calcium metabolism disorders

Outcome Measures

Primary Outcomes (1)

• Evaluate the associations between magnesium intake, magnesium stores, fractional magnesium absorption and calcium homeostasis.

  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.

  0-12 months

Secondary Outcomes (3)

• Does vitamin D therapy have a differential impact on calcium absorption that is dependent on magnesium stores?

  0-12 months

• Assessing relationships between magnesium status and bone mineral density.

  0-12 months

• Evaluate how magnesium status impacts the relationship between vitamin D levels and parathyroid hormone levels.

  0-12 months

Study Arms (3)

High dose vitamin D

ACTIVE COMPARATOR

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.

Dietary Supplement: vitamin D3

Low dose vitamin D

ACTIVE COMPARATOR

800 IU vitamin D3 every day of an approximate 365-day treatment.

Dietary Supplement: vitamin D3

Placebo

PLACEBO COMPARATOR

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.

Dietary Supplement: vitamin D3

Interventions

vitamin D3 DIETARY_SUPPLEMENT

pharmaceutical grade D3

Also known as: Cholecalciferol

High dose vitamin D; Low dose vitamin D; Placebo

Eligibility Criteria

• Age: 30 Years - 75 Years
• Sex: female
• Healthy Volunteers: Yes
• Age Groups: Adult (18-64), Older Adult (65+)

You may qualify if:

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

You may not qualify if:

• identical to those covered in HSC #2009-0055

Sponsors & Collaborators

• University of Wisconsin, Madison: lead
• National Institutes of Health (NIH): collaborator
• National Institute on Aging (NIA): collaborator

Study Sites (1)

University of Wisconsin-Madison Hospital, Clinical Research Unit, Osteoporosis Research Center

Madison, Wisconsin, 53705, United States

Location

Related Publications (1)

• 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.

  PMID: 24500940 BACKGROUND

MeSH Terms

Conditions

Magnesium Deficiency; Calcium Metabolism Disorders

Interventions

Cholecalciferol

Condition Hierarchy (Ancestors)

Deficiency Diseases; Malnutrition; Nutrition Disorders; Nutritional and Metabolic Diseases; Metabolic Diseases

Intervention Hierarchy (Ancestors)

Cholestenes; Cholestanes; Steroids; Fused-Ring Compounds; Polycyclic Compounds; Sterols; Vitamin D; Secosteroids; Membrane Lipids; Lipids

Study Officials

• Karen E Hansen, M.D., M.S.

  University of Wisconsin-Madison, Department of Medicine, Division of Rheumatology

  PRINCIPAL INVESTIGATOR

Study Design

• Study Type: interventional
• Phase: phase 4
• Allocation: RANDOMIZED
• Masking: DOUBLE
• Who Masked: PARTICIPANT, INVESTIGATOR
• Purpose: TREATMENT
• Intervention Model: PARALLEL
• Sponsor Type: OTHER
• Responsible Party: SPONSOR

Study Record Dates

• First Submitted: May 4, 2012
• First Posted: May 8, 2012
• Study Start: May 1, 2012
• Primary Completion: August 1, 2013
• Study Completion: August 1, 2014
• Last Updated: November 1, 2016

Record last verified: 2016-10

Locations

US (1)