Importance of Dosing Regimen for the Effect of Vitamin D Supplementation

May 23, 2018 updated by: University of Tromso
Vitamin D is a hormone with effects not only on the skeleton, but on most tissues in the body. Lack of vitamin D is associated with cardio-vascular disease (CVD), type 2 diabetes, cancer, infectious and immunological diseases, as well as risk factors for these diseases. However, intervention studies with vitamin D have been inconclusive regarding diseases and risk factors. This could be due to inclusion of subjects already vitamin D sufficient, and short and underpowered studies. In addition, there are indications that the dosing regimens may be important, so that daily doses with vitamin D are more efficient than intermittent doses, which so far have been generally used. This could be related to the concentration of circulating and thereby intracellular vitamin D concentrations, which probably is dependent on daily vitamin D doses. This will be tested in the present study where 60 subjects will be randomized to vitamin D 160 000 once, vitamin D 4000 IU/day, or placebo for four weeks. The primary endpoints will be effects on serum hepcidin and plasma cathelicidin after 4 weeks, with effects on serum PTH, RNA expression and microRNA in peripheral blood, telomerase activity in peripheral blood mononuclear cells and the ration between serum 1,25(OH)2D and 24,25(OH)2D as secondary endpoints.

Study Overview

Status

Status

Indicates the current recruitment status or the expanded access status.
Completed

Conditions

Conditions

The disease, disorder, syndrome, illness, or injury that is being studied. On ClinicalTrials.gov, conditions may also include other health-related issues, such as lifespan, quality of life, and health risks.

Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.

Study Type

Study Type

Describes the nature of a clinical study. Study types include interventional studies (also called clinical trials), observational studies (including patient registries), and expanded access.
Interventional

Enrollment (Actual)

Enrollment

The number of participants in a clinical study. The "anticipated" enrollment is the target number of participants that the researchers need for the study.
61

Phase

Phase

The stage of a clinical trial studying a drug or biological product, based on definitions developed by the U.S. Food and Drug Administration (FDA). The phase is based on the study's objective, the number of participants, and other characteristics. There are five phases: Early Phase 1 (formerly listed as Phase 0), Phase 1, Phase 2, Phase 3, and Phase 4. Not Applicable is used to describe trials without FDA-defined phases, including trials of devices or behavioral interventions.
  • Phase 3

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

  • Norway
      • Tromsø, Norway, 9038
        • University Hospital of North Norway

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

Eligibility Criteria

The key requirements that people who want to participate in a clinical study must meet or the characteristics they must have. Eligibility criteria consist of both inclusion criteria (which are required for a person to participate in the study) and exclusion criteria (which prevent a person from participating). Types of eligibility criteria include whether a study accepts healthy volunteers, has age or age group requirements, or is limited by sex.

Ages Eligible for Study

20 years to 70 years (Adult, Older Adult)

Accepts Healthy Volunteers

No

Genders Eligible for Study

All

Description

Inclusion Criteria:- Males and females 20 - 70 years

  • 20 kg/m2 > BMI < 35 kg/m2
  • systolic BP < 175 mmHg, diastolic BP < 105 mmHg
  • Serum 25(OH)D level < 50 nmol/L. Serum 25(OH)D < 50 nmol/L is considered as vitamin D deficiency, and accordingly, effects of vitamin D supplementation will be easier to detect than if the included subjects were vitamin D sufficient.
  • Hgb, SR, CRP, creatinine < 130 umol/L in males, < 120 umol/L in females, calcium, FT4 and TSH within the normal reference range; ASAT < 90 mU/L ALAT < 140 U/L, HbA1c < 6.6 %
  • The subjects must agree not to take any vitamin D supplementation, including cod liver oil or "mølje", use solarium or go on sunny vacation during the intervention period.

Exclusion Criteria:

  • subjects allergic to peanuts
  • subjects with primary hyperparathyroidism
  • granulomatous diseases (sarcoidosis, tuberculosis, Wegner's granulomatosis)
  • diabetes
  • renal stones the last five years
  • subjects seriously ill (or with chronic disease) and unfit for participation in the study (as judged by one of the study doctors)
  • subjects using vitamin D supplements exceeding 800 IU per day or active vitamin D drugs (Rocaltrol or Etalpha)
  • pregnancy

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: Prevention
  • Allocation: Randomized
  • Interventional Model: Parallel Assignment
  • Masking: Quadruple

Arms and Interventions

Participant Group / Arm

Participant Group / Arm

A group or subgroup of participants in a clinical trial that receives a specific intervention/treatment, or no intervention, according to the trial's protocol.
Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.
Experimental: vitamin D bolus
vitamin D 160 000 IU given as bolus
Drug: Vitamin D
vitamin D given as bolus versus daily dosing
Experimental: vitamin D daily
vitamin D 4000 IU daily for 28 days
Drug: Vitamin D
vitamin D given as bolus versus daily dosing
Placebo Comparator: placebo
identical looking as vitamin d
Drug: Placebo
identical looking as vitamin D

What is the study measuring?

Primary Outcome Measures

Primary Outcome Measures

In a clinical study's protocol, the planned outcome measure that is the most important for evaluating the effect of an intervention/treatment. Most clinical studies have one primary outcome measure, but some have more than one.
Outcome Measure
Measure Description
Time Frame
Hepcidin change
Time Frame: 4 weeks
Difference between vitamin D given as a bolus 160 000IU vs 4000 IU regarding change in serum hepcidin
4 weeks

Secondary Outcome Measures

Secondary Outcome Measures

In a clinical study's protocol, a planned outcome measure that is not as important as the primary outcome measure for evaluating the effect of an intervention but is still of interest. Most clinical studies have more than one secondary outcome measure.
Outcome Measure
Measure Description
Time Frame
Difference in serum PTH after 1 month
Time Frame: 4 weeks
Difference between vitamin D given as a bolus 160 000IU vs 4000 IU regarding change in serum PTH, cathelicidin, RNA expression and micro RNA in peripheral blood, telomerase activity and the ratio between 1,25(OH)2D and 24,25(OH)2D, after 1 month
4 weeks
Difference in micro RNA Expression after 1 month
Time Frame: 4 weeks
Difference between vitamin D given as a bolus 160 000IU vs 4000 IU
4 weeks
Difference in serum cathelicidin after 1 month
Time Frame: 4 weeks
Difference between vitamin D given as a bolus 160 000IU vs 4000 IU
4 weeks
Difference in RNA Expression after 1 month
Time Frame: 4 weeks
Difference between vitamin D given as a bolus 160 000IU vs 4000 IU
4 weeks
Difference in telomerase Activity after 1 month
Time Frame: 4 weeks
Difference between vitamin D given as a bolus 160 000IU vs 4000 IU
4 weeks
Difference in ratio between 1,24(OH)2D and 24,24(OH)2D after 1 month
Time Frame: 4 weeks
Difference between vitamin D given as a bolus 160 000IU vs 4000 IU
4 weeks

Collaborators and Investigators

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

Sponsor

Sponsor

The organization or person who initiates the study and who has authority and control over the study.
University of Tromso

Investigators

Investigators

A researcher involved in a clinical study. Related terms include site principal investigator, site sub-investigator, study chair, study director, and study principal investigator.
  • Principal Investigator: rolf jorde, MD PhD, UiT, Tromsø

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 (Actual)

Study Start

The actual date on which the first participant was enrolled in a clinical study. The "anticipated" study start date is the date that the researchers think will be the study start date.
December 1, 2017

Primary Completion (Actual)

Primary Completion

The date on which the last participant in a clinical study was examined or received an intervention to collect final data for the primary outcome measure. Whether the clinical study ended according to the protocol or was terminated does not affect this date. For clinical studies with more than one primary outcome measure with different completion dates, this term refers to the date on which data collection is completed for all the primary outcome measures. The "anticipated" primary completion date is the date that the researchers think will be the primary completion date for the study.
April 1, 2018

Study Completion (Actual)

Study Completion

The date on which the last participant in a clinical study was examined or received an intervention/treatment to collect final data for the primary outcome measures, secondary outcome measures, and adverse events (that is, the last participant's last visit). The "anticipated" study completion date is the date that the researchers think will be the study completion date.
May 1, 2018

Study Registration Dates

First Submitted

First Submitted

The date on which the study sponsor or investigator first submitted a study record to ClinicalTrials.gov. There is typically a delay of a few days between the first submitted date and the record's availability on ClinicalTrials.gov (the first posted date).
June 15, 2017

First Submitted That Met QC Criteria

First Submitted That Met QC Criteria

The date on which the study sponsor or investigator first submits a study record that is consistent with National Library of Medicine (NLM) quality control (QC) review criteria. The sponsor or investigator may need to revise and submit a study record one or more times before NLM's QC review criteria are met. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
September 1, 2017

First Posted (Actual)

First Posted

The date on which the study record was first available on ClinicalTrials.gov after National Library of Medicine (NLM) quality control (QC) review has concluded. There is typically a delay of a few days between the date the study sponsor or investigator submitted the study record and the first posted date.
September 5, 2017

Study Record Updates

Last Update Posted (Actual)

Last Update Posted

The most recent date on which changes to a study record were made available on ClinicalTrials.gov. There may be a delay between when the changes were submitted to ClinicalTrials.gov by the study's sponsor or investigator (the last update submitted date) and the last update posted date.
May 24, 2018

Last Update Submitted That Met QC Criteria

Last Update Submitted That Met QC Criteria

The most recent date on which the study sponsor or investigator submitted changes to a study record that are consistent with National Library of Medicine (NLM) quality control (QC) review criteria. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
May 23, 2018

Last Verified

Last Verified

The most recent date on which the study sponsor or investigator confirmed the information about a clinical study on ClinicalTrials.gov as accurate and current. If a study with a recruitment status of recruiting; not yet recruiting; or active, not recruiting has not been confirmed within the past 2 years, the study's recruitment status is shown as unknown.
September 1, 2017

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

Other Study ID Numbers

Identifiers or ID numbers other than the NCT number that are assigned to a clinical study by the study's sponsor, funders, or others. These numbers may include unique identifiers from other trial registries and National Institutes of Health grant numbers.
  • TromsøEndo-2017-1

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

No

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

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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Conditions

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