Vitamin D Intervention in Young Adults With Severe Childhood-onset Obesity

Study Overview
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Brief Summary
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Obesity is associated with lower total serum 25-hydroxycholecalciferol (S-25OHD) concentration. However, the impact of obesity on free S-25OHD is inadequately studied. A direct assay for free 25OHD was introduced recently. The aim of the study was to evaluate differences in vitamin D metabolism between young adults with severe childhood-onset obesity and normal-weight controls. Half of the obese subjects and controls will receive placebo and the other half will receive vitamin D3 50 µg daily for 12 weeks.

Official Title
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Vitamin D Intervention in Young Adults With Severe Childhood-onset Obesity

Conditions
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Obesity

Intervention / Treatment
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* Dietary Supplement: vitamin D
* Dietary Supplement: Placebo


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: weight-for-height ratio exceeding 60% before the age of 7 years, according to Finnish growth standards and persistence of severe obesity for at least three years in childhood referral to the Children's Hospital, Helsinki University Hospital due to severe obesity at the age of 7 years lived in the greater Helsinki area Exclusion Criteria: endocrine or genetic disorders underlying obesity (e.g. Prader Willi syndrome, pseudohypoparathyroidism, hypothyroidism, hypercortisolism, diabetes

Ages Eligible for Study
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Minimum Age: 15 Years
Maximum Age: 25 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Prevention
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Double


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Placebo Comparator: Obese, placebo<br>Placebo daily for 12 weeks | Dietary Supplement: Placebo<br> <br> |
| Active Comparator: Obese, vitamin D<br>Vitamin D3 50 µg / daily for 12 weeks | Dietary Supplement: vitamin D<br> <br> * Other names: cholecalciferol;|
| Placebo Comparator: Control, placebo<br>Placebo daily for 12 weeks | Dietary Supplement: Placebo<br> <br> |
| Active Comparator: Control, vitamin D<br>Vitamin D3 50 µg / daily for 12 weeks | Dietary Supplement: vitamin D<br> <br> * Other names: cholecalciferol;|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| change in S-25OHD | change in total and free S-25OHD concentrations between obese and controls | baseline, 6 and 12 weeks | 
| baseline S-25OHD | differences in total and free S-25OHD between obese and controls | baseline | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| baseline vitamin D-binding protein (DBP) | differences in DBP between obese and controls | baseline | 
| correlation between S-25OHD and calcium, phosphate, parathyroid hormone (PTH) and osteocalcin | correlation between S-25OHD (total and free) and calcium, phosphate, PTH and osteocalcin | baseline, 6 and 12 weeks | 
| change in vitamin D-binding protein (DBP) | change in DBP concentrations between obese and controls | baseline, 6 and 12 weeks | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Vitamin D