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Does Treatment of Hypovitaminosis D Increase Calcium Absorption?

The safety and scientific validity of this study is the responsibility of the study sponsor and investigators. Listing a study does not mean it has been evaluated by the U.S. Federal Government. Read our disclaimer for details. Identifier: NCT00581828
Recruitment Status : Completed
First Posted : December 28, 2007
Results First Posted : September 14, 2012
Last Update Posted : September 14, 2012
Information provided by (Responsible Party):
University of Wisconsin, Madison

Brief Summary:
The purpose is to perform a one-year study designed to assess whether treatment of hypovitaminosis D increases intestinal absorption of calcium, subsequent retention of calcium within bone, decreases bone turnover, and favorably impacts upon skeletal muscle mass, functional status, measures of physical function and quality of life. I hypothesize that treatment of hypovitaminosis D results in improved intestinal calcium absorption, greater retention of calcium within the bone reservoir and improved physical function, quality of life and muscle mass.

Condition or disease Intervention/treatment Phase
Osteoporosis Osteopenia Vitamin D Deficiency Hypoparathyroidism Hypercalciuria Hypercalcemia Drug: Vitamin D Phase 4

Detailed Description:

Postmenopausal women with vitamin D insufficiency will participate in this one-year study. We will study the change in intestinal calcium absorption from baseline (vitamin D insufficiency) to follow up (vitamin D repletion and whether increased absorption results in subsequent increased retention of calcium within bone over the one-year interval as measured by bone densitometry. We will also study the effect of vitamin D repletion upon whole body muscle mass, quality of life and physical function.

A review of medical records and a screening visit will determine eligibility. Eligible and consenting subjects will present to the GCRC in the early morning and following baseline labs, will consume breakfast with a glass of orange juice enriched with a stable calcium isotope, and will receive 3 mg of another stable calcium isotope by intravenous injection. Over the next eight hours, blood will be taken a total of 9 more times and over the first 24 hours, all urine and stool will be collected for measurement of its calcium content.

Subsequently for the next five days, women will collect three urine specimens daily. Women will then receive vitamin D to treat vitamin D deficiency. Once vitamin D repletion is accomplished, all women will repeat their 24-hour visit and subsequent five-day urine collections. Women will maintain vitamin D repletion by taking a twice monthly tablet (50,000 IU) of vitamin D2. To confirm vitamin D repletion and safety over the full one year study, additional study visits will occur at 3, 6 and 12 months.

A bone density test at screening and twelve months will allow us to assess the effect of vitamin D repletion on whole body bone mass and skeletal mass. At each GCRC stay, 3, 6 and 12 months, women will complete questionnaires regarding quality of life and functional status and will perform the Timed Up and Go Test. Because we wish to maintain and confirm constant calcium intake throughout the one- year study, women will complete a calcium questionnaire at baseline, 3, 6 and 12 months.

With each subject's consent, we will collect one tube of blood and isolate its DNA. When sufficient knowledge is available regarding the pathophysiologic mechanisms whereby genetic polymorphisms impact calcium homeostasis, we will test for such DNA polymorphisms and relate genetic information with other data collected on calcium homeostasis.

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Study Type : Interventional  (Clinical Trial)
Actual Enrollment : 19 participants
Allocation: N/A
Intervention Model: Single Group Assignment
Masking: None (Open Label)
Primary Purpose: Treatment
Official Title: Does Treatment of Hypovitaminosis D Increase Calcium Absorption?
Study Start Date : January 2005
Actual Primary Completion Date : July 2008
Actual Study Completion Date : December 2008

Arm Intervention/treatment
Experimental: 1
Subjects received vitamin D (50,000 IU daily for 15 days) and maintenance dose vitamin D (50,000 IU twice monthly for 10 months).
Drug: Vitamin D
50,000 IU po qd for 15 days and 50,000 IU po twice month for 10 months (until final study visit at one year)
Other Names:
  • Vitamin D2
  • Ergocalciferol

Primary Outcome Measures :
  1. Change in Intestinal Calcium Absorption From Baseline to One Month [ Time Frame: 1 month ]
    percent and true fractional calcium absorption

Information from the National Library of Medicine

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Ages Eligible for Study:   Child, Adult, Older Adult
Sexes Eligible for Study:   Female
Accepts Healthy Volunteers:   Yes

Inclusion Criteria:

  • women at least five years past onset of menopause, defined as date of last menses
  • serum 25(OH)D 16-24 ng/ml by reverse phase HPLC
  • calcium intake < or = 1,100 mg daily

Exclusion Criteria:

  • Intake of >1,100 mg of calcium per day through the combination of diet and supplements
  • Hypercalcemia (baseline serum calcium above the normal reference range)
  • Nephrolithiasis, documented in the medical record or by patient report
  • Inflammatory bowel disease, malabsorption, chronic diarrhea, or use of antibiotics within the past month
  • Creatinine >2.0 mg/dL
  • Hypercalciuria (baseline urine calcium: creatinine ratio >0.25)
  • Current use of medications known to interfere with vitamin D and/or calcium metabolism, including oral steroids or anticonvulsants
  • Ongoing or recent (past six months) use of bisphosphonates, estrogen compounds, calcitonin or teriparatide, as these compounds may independently affect retention of calcium within bone
  • Diagnosis of, or evidence for, osteomalacia, manifest by serum 25(OH)D < 16 ng/ml or the presence of at least two of the following blood tests: low calcium, low phosphorus, or elevated alkaline phosphatase (23).
  • Prior adult clinical fragility fracture or baseline T-score below -3.0 at the lumbar spine or femur

Information from the National Library of Medicine

To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.

Please refer to this study by its identifier (NCT number): NCT00581828

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United States, Wisconsin
University of Wisconsin Hospital and Clinics
Madison, Wisconsin, United States, 53792
Sponsors and Collaborators
University of Wisconsin, Madison
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Principal Investigator: Karen E Hansen, MD University of Wisconsin, Madison
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Responsible Party: University of Wisconsin, Madison Identifier: NCT00581828    
Other Study ID Numbers: 2005-0159
First Posted: December 28, 2007    Key Record Dates
Results First Posted: September 14, 2012
Last Update Posted: September 14, 2012
Last Verified: September 2012
Keywords provided by University of Wisconsin, Madison:
Calcium Absorption
Intestinal Absorption of Calcium
Fractional Calcium Absorption
Stable Calcium Isotopes
Hypovitaminosis D
Vitamin D
Bone Mineral Density
Physical Function
Additional relevant MeSH terms:
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Bone Diseases, Metabolic
Vitamin D Deficiency
Bone Diseases
Musculoskeletal Diseases
Metabolic Diseases
Deficiency Diseases
Nutrition Disorders
Parathyroid Diseases
Endocrine System Diseases
Calcium Metabolism Disorders
Water-Electrolyte Imbalance
Urological Manifestations
Vitamin D
Physiological Effects of Drugs
Bone Density Conservation Agents
Calcium-Regulating Hormones and Agents