Personalized Vitamin D Supplementation in European and African Americans

Completed · Not applicable

Conditions studied: Vitamin D Deficiency

In brief

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.

Key facts

Study ID

NCT02362269

Run by

University of Wisconsin, Madison

People needed

169

Starts

2015-10-30

Expected to finish

2019-05-03

Last updated by the study team

2020-12-01

Who can join

Age: any. Sex: female. Healthy volunteers: accepted.

You may qualify if…

• 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

You may not qualify if…

• 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)

Where it is running

• University of Wisconsin Osteoporosis Clinical Research Program — Madison, Wisconsin, United States
• Medical College of Wisconsin — Milwaukee, Wisconsin, United States

Full record on ClinicalTrials.gov

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