Effects of Vitamin D Supplementation in Obesity
Obesity is an increasing health problem with numerous metabolic complications. Vitamin D deficiency is common in obesity, and in epidemiological studies vitamin D deficiency has been linked to metabolic complications, such as type 2 diabetes, insulin resistance and cardiovascular disease, as well as myopathy, osteoporosis and depression. In obesity, a low grade inflammation is present in the fat tissue, thereby releasing inflammatory molecules to the blood stream. In cell line studies as well as small clinical studies vitamin D has been shown to have the ability to reduce inflammation and cell growth.
In the present study the investigators wish to investigate the effect of vitamin D on fat-, muscle and bone metabolism. 30 healthy obese subjects will be treated with cholecalciferol 175 micrograms daily for 6 months and will be compared with 30 healthy obese subjects treated with placebo.
The investigators hypothesize that restoring vitamin D levels in vitamin D deficient obese subject will reduce inflammation and thereby reduce obesity-related complications.
The effect will be evaluated as follows:
- Levels of circulating inflammatory markers will be examined in blood samples collected prior to and after treatment.
- Effects on fat- and muscle metabolism will be evaluated in fat- and muscle samples taken before and after treatment.
- Effects on fat distribution will be evaluated by MRI scan before and after treatment.
- Effects on insulin sensitivity will be evaluated by hyperinsulinaemic euglycaemic clamp performed on a subgroup of subjects with impaired fasting glucose.
- Effects on bone marrow density will be evaluated by DEXA scans before and after treatment.
- Effects on quality of life and depression score will be evaluated by questionnaires used before and after treatment.
Vitamin D Deficiency
|Study Design:||Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Double Blind (Subject, Investigator)
Primary Purpose: Treatment
|Official Title:||Effects of Vitamin D Supplementation in Vitamin D Deficient Obese Subject.|
- Effect on circulating inflammatory markers [ Time Frame: 6 months ] [ Designated as safety issue: No ]
- change in fat distribution [ Time Frame: 6 months ] [ Designated as safety issue: No ]
- change in insulin sensitivity [ Time Frame: 6 months ] [ Designated as safety issue: No ]
- change in bone mineral density [ Time Frame: 6 months ] [ Designated as safety issue: No ]
- change in quality of life [ Time Frame: 6 months ] [ Designated as safety issue: No ]
- change in depression score [ Time Frame: 6 months ] [ Designated as safety issue: No ]
- change in muscle function [ Time Frame: 6 months ] [ Designated as safety issue: No ]
- change in fat- and muscle metabolism [ Time Frame: 6 months ] [ Designated as safety issue: No ]
|Study Start Date:||January 2010|
|Study Completion Date:||July 2012|
|Primary Completion Date:||December 2011 (Final data collection date for primary outcome measure)|
|Active Comparator: cholecalciferol||
oral cholecalciferol tablets of 175 micrograms daily for 6 months
Other Name: vitamin D
|Placebo Comparator: placebo||
oral placebo tablets similar to active comparator
|Dept. of Endocrinology and Metabolism, Aarhus University Hospital|
|Principal Investigator:||Louise Wamberg, Dr.||Aarhus University Hospital|