A Phase 4 interventional study of Vitamin D supplementation and Placebo in Obesity, sponsored by Centre Hospitalier Universitaire de Nīmes. Completed at 2 sites in France. Open to participants aged 11 Years to 17 Years, including healthy volunteers. Per ClinicalTrials.gov, last updated 2025-11-19.
Sponsored by Centre Hospitalier Universitaire de Nīmes · Phase 4, Interventional, and Treatment
The main objective of this study is to analyze in a population of obese adolescents, the effect of vitamin D3 supplementation in addition to lifestyle and dietary management on vascular function assessed by the change between M0 and M3 of endothelium-dependent vasorelaxation measured at the brachial artery (Flow-Mediated Dilation).
The secondary objectives of this study are:
A. To analyze in obese adolescents, the effect of the addition of vitamin D3 supplementation on metabolic and vascular function.
B. To compare the relationships between food intake, metabolic, inflammatory, oxidative stress and vitamin D status, and vascular dysfunction between obese and normal weight subjects.
C. To evaluate the effects of sun exposure variations on relationships described in Objective B by comparing the observed parameters at baseline and at the end of the three month follow-up period, in non-supplemented obese adolescents and adolescents of normal weight.
D. To identify biomarkers (metabolic signatures) in obese adolescents associated with vitamin D deficiency and vascular function.
E. To evaluate in obese adolescents, the effects of vitamin D supplementation on the metabolome (metabolic signature).
F. To evaluate the effects of lifestyle and dietary management on these biomarkers (in the "control group").
For these targets (A to F), all teenagers will be classified according to three levels of skin pigmentation.
G. Establish a biobank of samples taken at baseline and at 3 months.
6,296 studies on the registry are indexed under Obesity; 1,692 are open to participants now.
This study's enrollment of 49 is below the median of 78 across 4,878 interventional studies indexed under Obesity.
Browse Obesity studies →Centre Hospitalier Universitaire de Nīmes is the lead sponsor of 587 studies on the registry; 96 are open to participants now.
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General Inclusion Criteria:
Inclusion criteria for the patient population
Inclusion criteria for the control population
Exclusion Criteria:
Non-obese patients will be recruited and frequency matched to obese groups according to sex and level of sexual maturation. Intervention: Normal control
Other: Normal control
Subjects randomized to this group will receive vitamin D supplementation. They are recruited from the St Pierre Institute at Palavas-les-Flots, France. Intervention: 3 months lifestyle and dietary management Intervention: Vitamin D supplementation
Drug: Vitamin D supplementation · Other: 3 months lifestyle and dietary management
Subjects randomized to this group will receive a placebo supplement. They are recruited from the St Pierre Institute at Palavas-les-Flots, France. Intervention: 3 months lifestyle and dietary management Intervention: Placebo
Drug: Placebo · Other: 3 months lifestyle and dietary management
Patients randomized to this group will receive 4000 UI of Vitamin D3 per day for 90 days.
Patients randomized to this group will receive placebo for 90 days.
Lifestyle and dietary management at the Saint Pierre Institute (Palavas-les-Flots, France) occurs for three months. Nutritionally speaking, each child or adolescent receives a controlled and balanced diet, consistent with the recommendations appropriate for his/her age, slightly hypocaloric or normocaloric. This dietary approach is complemented by a nutrition education program and supervision by a doctor and a dietician. Three hours of exercise training per week are scheduled; these sessions include adapted aerobic activities supervised by instructors and educators at the center.
Patients in this group do not have experimental intervention in order to provide measures of a real-life control group.
Change from baseline in Flow Mediated Dilation (%) at the brachial artery
Time frame: 3 months
Change from baseline in Nitrate Mediated Dilation (%) at the brachial artery
Time frame: 3 months
Change from baseline in carotid compliance (mm^2mmHg^-1)
Time frame: 3 months
Change from baseline in brachial compliance (mm^2mmHg^-1)
Time frame: 3 months
Change from baseline in arterial wave speed (m*s^-1)
Time frame: 3 months
Usual Vitamin D intake according to food questionnaire
Time frame: Baseline
Change from baseline in blood 25(OH)D levels (mmol*L^-1)
Time frame: 3 months
Change from baseline in blood parathyroid hormone levels (mmol*L^-1)
Time frame: 3 months
Change from baseline in serum calcium levels (mmol*L^-1)
Time frame: 3 months
Change from baseline in blood total protein levels (g*L^-1)
Time frame: 3 months
Change from baseline in Homeostatic model assessment Insulin Resistance
Time frame: 3 months
Change from baseline in the ratio Low Density Lipoprotein/High Density Lipoprotein
Time frame: 3 months
Change from baseline in Triglyceride levels
Time frame: 3 months
Change from baseline in Acetylcholine-Cutaneous Blood Flow peak
Time frame: 3 months
Change from baseline in Sodium nitroprussiate-Cutaneous Blood Flow peak (%)
Time frame: 3 months
Change from baseline in Insulin-Cutaneous Blood Flow peak (%)
Time frame: 3 months
Change from baseline in TNF-alpha (pg*mL^-1)
Time frame: 3 months
Change from baseline in IL-6 (pg*mL^-1)
Time frame: 3 months
Change from baseline in High sensitivity C-reactive protein (pg*mL^-1)
Time frame: 3 months
Change from baseline in leptin (pg*mL^-1)
Time frame: 3 months
Change from baseline in adiponectin (pg*mL^-1)
Time frame: 3 months
Change from baseline in SuperOxyde Dismutase (U*gHb^-1)
Time frame: 3 months
Change from baseline in Isoprostanes (ng*L^-1)
Time frame: 3 months
Change from baseline in nitrite-nitrate (µmol*L^-1)
Time frame: 3 months
Change from baseline in PAI-1 (µmol*L^-1)
Time frame: 3 months
Metabolomic profile
Time frame: baseline
Metabolomic profile
Time frame: 3 months
This study is completed, as verified in Jun 2017. You cannot join it, but the record below documents what was studied.
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Centre Hospitalier Universitaire de Nīmes