Immune and Metabolic Effects of Vitamin D Supplementation in Healthy Humans

Phase 4

Completed

• Conditions: Healthy Humans
• Interventions: Drug: Placebo; Drug: Cholecalciferol

• Registration Number: NCT01248442
• Lead Sponsor: Medical University of Graz

Brief Summary

In this placebo controlled study the investigators aim to investigate the effect of a 3 month vitamin D supplementation on parameters of the immune, endocrine and metabolic system in healthy women and men. Vitamin D. In a pilot study the investigators showed an increase of certain immune cells, which regulate immunotolerance, the investigators therefore try to confirm these results with a placebo group. Furthermore the investigators assess the effect of vitamin D on the glucose metabolism and hormone levels.

Detailed Description

This is a randomized double-blind placebo controlled trial, with the aim to investigate the effect of a Vitamin D supplementation on parameters of the immune, endocrine and metabolic system in healthy humans without diabetes and obesity.

The primary aim is to assess the effect of vitamin D supplementation of the number and function of peripheral regulatory T-cells (Tregs). The investigators will measure the Tregs at baseline and monthly for 3 months. Furthermore the investigators assess additional immune cells from the adaptive immunosystem.

Furthermore the investigators will perform a standard mixed meal tolerance test at baseline and 3 months following the supplementation in order to assess the insulin secretion in vivo.

Study Timeline

• Study Start: 2009-11
• Primary Completion: 2010-06
• Study Completion: 2010-06
• Study First Submitted: 2010-11-24
• Study First Submitted QC: 2010-11-24
• Study First Posted: 2010-11-25
• Status Verified: 2012-02
• Last Update Submitted: 2012-02-08
• Last Update Posted: 2012-02-09

Recruitment & Eligibility

• Status: COMPLETED
• Sex: All
• Target Recruitment: 60

Inclusion Criteria

• Age >= 10 years
• healthy subjects without chronic disease

Exclusion Criteria

• Hypercalcemia >2,65 mmol/L
• pregnancy and lactation period
• acute infections
• chronic disease requiring treatment

Study & Design

• Study Type: INTERVENTIONAL
• Study Design: PARALLEL

Arm && Interventions

Group	Intervention	Description
Placebo	Placebo	-
Cholecalciferol	Cholecalciferol	-

Primary Outcome Measures

Name	Time	Method
Increase and function of peripheral regulatory T-cells	3 months	The level and function of the regulatory T-cells will be compared between the two groups.

Secondary Outcome Measures

Name	Time	Method
immunophenotyping	3 months	The effect of vitamin D on circulating immune cells and cytokine secretion will be measured at basal and after 3 months.
Renin and aldosterone concentrations	3 months	serum renin and aldosterone levels will be measured basal and after 3 months.
Insulin secretion	3 months	Insulin secretion assessed with a mixed meal tolerance test will be performed basal and after 3 months
calcium levels	3 months	serum calcium levels will be measured basal and monthly for 3 months.

Trial Locations

Locations (1)

Medical University Graz; 🇦🇹 Graz, Austria