Obesity, Vitamin D Deficiency
Conditions
Brief summary
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.
Interventions
oral cholecalciferol tablets of 175 micrograms daily for 6 months
oral placebo tablets similar to active comparator
Sponsors
Study design
Eligibility
Inclusion criteria
* Healthy obese (BMI 30 - 45 kg/m2) * 25(OH) vitamin D \< 50 nmol/l
Exclusion criteria
* Diabetes, * Pregnancy or non-safe contraception, * Vitamin D treatment within 3 months, * Hypercalcaemia, renal failure, * Liver failure, non eligibility for MRI-scan, * Severe osteomalacia, * Allergy towards study drug
Design outcomes
Primary
| Measure | Time frame |
|---|---|
| Effect on circulating inflammatory markers | 6 months |
Secondary
| Measure | Time frame |
|---|---|
| change in insulin sensitivity | 6 months |
| change in bone mineral density | 6 months |
| change in quality of life | 6 months |
| change in fat distribution | 6 months |
| change in muscle function | 6 months |
| change in fat- and muscle metabolism | 6 months |
| change in depression score | 6 months |
Countries
Denmark