Vitamin D Inadequacy in Rural Populations, Evaluation of Correction by Food Supplementation

November 23, 2011 updated by: University of Wisconsin, Madison

Vitamin D Inadequacy: Documentation in Rural Populations and Evaluation of Correction by Food Supplementation (Phase III; Manitowoc Prevalence Study)

The purpose of the research is to describe vitamin D levels and bone status in a rural Wisconsin population. It is probable that individuals of varying age and ethnicity require different amounts of D to achieve optimal status. These likely scenarios will be explored in various populations. We hypothesize that the increase in serum 25(OH)D resulting from daily D3 ingestion is less pronounced with advancing age and different in Native than Caucasian Americans. In addition, the women in the middle age group, between the ages of 55 and 65, will have ultrasound tests completed to assess the impact of the Vitamin D supplementation on cardiovascular health.

Study Overview

Study Type

Interventional

Enrollment (Actual)

108

Phase

  • Not Applicable

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Locations

    • Wisconsin
      • Madison, Wisconsin, United States, 53705
        • University of Wisconsin Osteoporosis Clinical and Research Program

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

55 years and older (Adult, Older Adult)

Accepts Healthy Volunteers

No

Genders Eligible for Study

Female

Description

Inclusion criteria:

  • Healthy, community-dwelling ambulatory women.
  • Able and willing to sign informed consent.
  • Ages: 20-30, 55-65 or >75
  • Baseline serum 25OHD concentration > 10 ng/ml and < 60 ng/ml
  • Not pregnant
  • Willing to avoid use of cod-liver oil and non-study vitamin D supplementation; standard multiple vitamins containing ≤ 400 IU used no more than once daily will be allowed.
  • Willing to utilize sunscreen of SPF-15 or higher when sun exposure for more than 15 minutes is expected.

Exclusion criteria:

  • Current hypercalcemia (serum calcium > 10.5 mg/dl) or untreated primary hyperparathyroidism.
  • History of nephrolithiasis
  • Baseline 24-hour urine calcium > 250 mg
  • Known risk factors for hypercalcemia, e.g., malignancy, tuberculosis, sarcoidosis, Paget's disease.
  • History of any form of cancer within the past five years with the exception of adequately treated squamous cell or basal cell skin carcinoma.
  • Renal failure; defined as a calculated creatinine clearance (using the Cockroft-Gault approach) of ≤ 25 ml/minute.
  • Severe end-organ disease, e.g., cardiovascular, hepatic, hematologic, pulmonary, etc., which might limit the ability to complete this study.
  • Treatment with any drug known to interfere with vitamin D metabolism, e.g., phenytoin, phenobarbital.
  • Known malabsorption syndromes, e.g., celiac disease, active inflammatory bowel disease, etc.
  • Known allergy to chocolate.
  • Use of medications known to alter bone turnover including bisphosphonates, estrogen, selective estrogen receptor modulators, parathyroid hormone, testosterone or calcitonin.
  • Treatment with high dose vitamin D (≥ 50,000 IU weekly) or any active metabolites of vitamin D, e.g., calcitriol, within six months of screening.
  • Use of tanning beds or salons or unwillingness to utilize sunscreen during periods of sun exposure of 15 minutes or longer.

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Treatment
  • Allocation: Randomized
  • Interventional Model: Single Group Assignment
  • Masking: Double

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Placebo Comparator: 1
low calorie (~60 calories) cookie-like disc containing 2,500 IU of vitamin D3, taken by mouth daily for 4 months
Active Comparator: 2. 2500 IU vitamin D in a food preparation
Daily ingestion of 2500 IU vitamin D in a food preparation.
low calorie (~60 calories) cookie-like disc containing 2,500 IU of vitamin D3, taken by mouth daily for 4 months

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Time Frame
the primary outcome is the proportion of postmenopausal women with D inadequacy defined by current consensus as a serum 25(OH)D < 30 ng/ml.
Time Frame: 2.5 years
2.5 years

Secondary Outcome Measures

Outcome Measure
Time Frame
Prevalence of Vitamin D insufficiency in rural populations and ethnic differences in response to vitamin D supplementation
Time Frame: 2.5 year
2.5 year
The relationship between vitamin D supplementation and cardiovascular disease.
Time Frame: 2.5 Years
2.5 Years

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Investigators

  • Principal Investigator: Neil Binkley, MD, University of Wisconsin - Institute on Aging

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start

August 1, 2007

Primary Completion (Actual)

August 1, 2011

Study Completion (Actual)

August 1, 2011

Study Registration Dates

First Submitted

January 7, 2008

First Submitted That Met QC Criteria

June 3, 2008

First Posted (Estimate)

June 4, 2008

Study Record Updates

Last Update Posted (Estimate)

November 24, 2011

Last Update Submitted That Met QC Criteria

November 23, 2011

Last Verified

November 1, 2011

More Information

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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