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Personalized Vitamin D Supplementation in European and African Americans

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: NCT02362269
Recruitment Status : Completed
First Posted : February 12, 2015
Last Update Posted : May 30, 2019
Medical College of Wisconsin
Information provided by (Responsible Party):
University of Wisconsin, Madison

Tracking Information
First Submitted Date  ICMJE January 22, 2015
First Posted Date  ICMJE February 12, 2015
Last Update Posted Date May 30, 2019
Actual Study Start Date  ICMJE October 30, 2015
Actual Primary Completion Date May 3, 2019   (Final data collection date for primary outcome measure)
Current Primary Outcome Measures  ICMJE
 (submitted: February 11, 2015)
Efficacy of the dosing algorithm in achieving total 25(OH)D as measured by the number of subjects ending with concentrations of 35-50 ng/mL [ Time Frame: Baseline visit, 3 month visit and the 6 month visit. ]
To validate the proposed vitamin D3 dosing algorithm, a vitamin D panel consisting of serum concentrations of vitamin D3 (cholecalciferol; an indicator of vitamin D3 absorption), 25(OH)D3, 25(OH)D2, the C3-epimer of 25(OH)D3 and 24,25(OH)2D as well as an assay to directly measure free serum 25(OH)D will be run on all the blood samples collected at the baseline, 3 month and 6 month visits.
Original Primary Outcome Measures  ICMJE Same as current
Change History
Current Secondary Outcome Measures  ICMJE Not Provided
Original Secondary Outcome Measures  ICMJE Not Provided
Current Other Pre-specified Outcome Measures Not Provided
Original Other Pre-specified Outcome Measures Not Provided
Descriptive Information
Brief Title  ICMJE Personalized Vitamin D Supplementation in European and African Americans
Official Title  ICMJE Personalized Vitamin D Supplementation in European and African Americans
Brief Summary The proposed study is a randomized, double-blind, controlled, multi-center clinical trial of six months of daily oral vitamin D3 (cholecalciferol). This study will randomize 334 community-dwelling post-menopausal women of European and African descent (~167 from each ancestry) in a 1:1 ratio between the control arm and the dosing algorithm arm using stratified block randomization with a block size of six and stratification by site (ancestry). The sample size of 334 includes 10% over-recruitment to allow for loss to follow-up. The European ancestry women will be seen in the Madison clinic and the African ancestry women will be seen in the Milwaukee clinic. The proposed study will focus on post-menopausal women because this is the subset of the population that both Dr. Engelman's and Dr. Binkley's preliminary data are drawn from. Moreover, 25(OH)D concentrations are typically lower in women and in older individuals, since production of vitamin D in the skin following sun exposure decreases with age. Therefore, this group of individuals is likely to benefit the most from vitamin D supplementation, especially when personalized based on biology using the proposed dosing algorithm.
Detailed Description Potential volunteers will be screened by telephone. Those meeting all inclusion and no exclusion criteria will be invited to a screening study visit. At screening, informed consent will be obtained. The study team will then collect the following to determine study eligibility: basic demographic information (age, ancestry, and education); medical history; medication and supplement use; and blood for screening 25(OH)D and calcium tests. At baseline, participants will be randomly assigned to the control or dosing algorithm group. Both participants and study staff who have contact with the participants will be blinded to group assignment. Follow-up visits will occur at three and six months. At baseline and follow-up visits, height and weight will be measured and blood will be drawn for the vitamin D panel, calcium, and PTH. Blood for DNA and body composition will only be obtained at the baseline visit. Participants will be asked to return all unused study supplements and compliance will be assessed at each follow-up visit by pill count. The control group will receive 2500 IU of vitamin D3 daily while the dosing algorithm group will initially receive 1000, 2500, or 4000 IU daily, with the initial dosing based on the 25(OH)D at baseline, and the dosing may be adjusted at the 3-month visit.
Study Type  ICMJE Interventional
Study Phase  ICMJE Not Applicable
Study Design  ICMJE Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Double (Participant, Investigator)
Primary Purpose: Treatment
Condition  ICMJE Vitamin D Deficiency
Intervention  ICMJE Dietary Supplement: Vitamin D
Gelcaps containing 1000, 2500, and 4000 IU of vitamin D3 will be obtained from Tischon corporation (Westbury, NY). The gelcaps will be protected from light and not stored above 25° C. Participants will be instructed to take their vitamin D3 gelcaps with supper daily. Compliance with study supplementation will be documented by pill count at the time of each study visits.
Study Arms  ICMJE
  • Active Comparator: Control Group
    The control group will receive 2500 IU of vitamin D3 daily.
    Intervention: Dietary Supplement: Vitamin D
  • Experimental: Dosing Algorithm Group
    The dosing algorithm group will initially receive 1000, 2500, or 4000 IU of vitamin D3 daily based on the baseline 25(OH)D. This group's dosing may be adjusted at the 3-month visit.
    Intervention: Dietary Supplement: Vitamin D
Publications * Not Provided

*   Includes publications given by the data provider as well as publications identified by Identifier (NCT Number) in Medline.
Recruitment Information
Recruitment Status  ICMJE Completed
Estimated Enrollment  ICMJE
 (submitted: February 11, 2015)
Original Estimated Enrollment  ICMJE Same as current
Actual Study Completion Date  ICMJE May 3, 2019
Actual Primary Completion Date May 3, 2019   (Final data collection date for primary outcome measure)
Eligibility Criteria  ICMJE

Inclusion Criteria:

  • Healthy, community-dwelling postmenopausal woman of self-reported European (Madison site) or African (Milwaukee site) descent
  • Able and willing to sign informed consent
  • Baseline serum 25(OH)D concentration of 10.0-29.9 ng/mL
  • Willing to not alter the amount of their baseline vitamin D supplementation during the course of this study
  • Willing to use sunscreen (SPF ≥15) when sun exposure of >15 minutes is expected during the months of May through September

Exclusion Criteria:

  • Diagnosis of kidney or liver disease (organs that metabolize vitamin D)
  • Current hypercalcemia (serum calcium ≥ 10.5 mg/dL) or other disorders that may affect vitamin D metabolism and predispose to hypercalcemia, i.e., sarcoidosis, active tuberculosis or other granulomatous disease.
  • Other chronic diseases or conditions potentially affecting vitamin D metabolism or absorption (inflammatory bowel disease, cystic fibrosis, ulcerative colitis, and malabsorptive surgery)
  • History of nephrolithiasis
  • Current use of medications that affect vitamin D metabolism (glucocorticoids, anticonvulsants, antifungals, and HIV/AIDS medications)
  • History of any form of cancer within the past two years with the exception of basal or squamous cell skin lesions, in situ tumors or thyroid cancer
  • Terminal illness/on hospice
  • Severe end-organ disease (e.g., cardiovascular, pulmonary, etc.), which may limit the ability to complete the study
  • 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; current use of multiple vitamins and other vitamin D supplements will be allowed.
  • Use of tanning beds or salons or unwillingness to utilize sunscreen during periods of sun exposure of 15 minutes or longer from May through September
  • Planned trips/vacations likely to be associated with substantial amounts of sun exposure during the course of the study (i.e., more than 500 miles south of Madison/Milwaukee)
Sex/Gender  ICMJE
Sexes Eligible for Study: Female
Ages  ICMJE Child, Adult, Older Adult
Accepts Healthy Volunteers  ICMJE Yes
Contacts  ICMJE Contact information is only displayed when the study is recruiting subjects
Listed Location Countries  ICMJE United States
Removed Location Countries  
Administrative Information
NCT Number  ICMJE NCT02362269
Other Study ID Numbers  ICMJE 2015-0047
Has Data Monitoring Committee Yes
U.S. FDA-regulated Product Not Provided
IPD Sharing Statement  ICMJE Not Provided
Responsible Party University of Wisconsin, Madison
Study Sponsor  ICMJE University of Wisconsin, Madison
Collaborators  ICMJE Medical College of Wisconsin
Investigators  ICMJE
Principal Investigator: Corinne Engelman, PhD University of Wisconsin, Madison
PRS Account University of Wisconsin, Madison
Verification Date May 2019

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