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The Pharmacokinetics of a Single Large Dose of Vitamin D3

Not Applicable
Completed
Conditions
Vitamin D Deficiency
Interventions
Drug: cholecalciferol.
Registration Number
NCT00473239
Lead Sponsor
Creighton University
Brief Summary

When people eat a meal, some, but not all of the calcium in that meal is absorbed, that is, moved into the bloodstream. When the skin is exposed to sunlight during summer months, Vitamin D is made there and then modified into more active forms by the liver and kidneys. These more active forms of Vitamin D improve calcium absorption. Many adults living in the U.S. have little or no sun exposure and are low in Vitamin D. A single dose of 100,000 IU of Vitamin D3 has been used both as empiric treatment for Vitamin D deficiency as well as in controlled trials without risk of raising blood calcium to dangerous levels.This study is to determine the serum levels of Vitamin D and 25-hydroxyvitamin D (vitamin D after it has been modified by the liver) that can be expected when Vitamin D3 is given as a single oral dose of 100,000 IU.

Detailed Description

The group receiving the supplement will be scheduled for short visits to our research center at baseline and days 1,3,5,7 and then weekly for 3 weeks and then every other week for 6 visits (total 14 visits in 4 months). The group not receiving supplement will be scheduled for short visits at baseline and in 4 months. At the beginning of the study we will measure your height, weight, skin color, and draw blood to measure your blood levels of Vitamin D, 25-hydroxyvitamin D, calcium and parathyroid hormone. At each visit we will draw blood to measure your blood levels of Vitamin D and 25-hydroxyvitamin D. There will be fourteen blood draws for a total of 280 cc of blood drawn (about 4 teaspoons drawn each time) in the supplemented group. There will be 2 blood draws in the group not receiving supplements for a total of 60 cc of blood drawn (about 4 teaspoons drawn each time).

Recruitment & Eligibility

Status
COMPLETED
Sex
All
Target Recruitment
40
Inclusion Criteria
  • healthy with limited sun exposure of less than 10 hours per week and daily milk consumption of less than 0.47 L (16 oz.).
Exclusion Criteria
  • those with granulomatous conditions, liver disease, kidney disease, or diabetes and those taking anticonvulsants, barbiturates, or steroids in any form.

Study & Design

Study Type
INTERVENTIONAL
Study Design
SINGLE_GROUP
Arm && Interventions
GroupInterventionDescription
cholecalciferolcholecalciferol.A single dose of 100,000 IU vitamin D
Primary Outcome Measures
NameTimeMethod
to assess the time course and response of serum 25-OHD with a single oral dose of 100,000 IU cholecalciferol.4 months
Secondary Outcome Measures
NameTimeMethod

Trial Locations

Locations (1)

Creighton University

🇺🇸

Omaha, Nebraska, United States

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