Vitamin D
Conditions
Keywords
Vitamin D, bone, cardiovascular status, nutritional status
Brief summary
Vitamin D is not seen anymore only as a phosphocalcic hormone, but also as having an effect on global health (anti-infective, anti-inflammatory, anti-tumour roles and cardiovascular protection). The link between vitamin D deficiency and osteomalacia lesions is well-known. In paediatrics, systematic vitamin D supplementation of infants and toddlers, associated with milk enrichment, has allowed an almost total disappearance of rickets. Vitamin D repletion was defined as the minimal concentration that enables the prevention of rickets in children and osteomalacia in adults, that is approximately 8 ng/mL (20 nmol/L). However, in 2010, most of the international experts agreed to set minimal threshold of 25 OH vitamin D serum concentration, higher than the one previously admitted, with a limit of 20 ng/mL (50 nmol/L) to define a vitamin D deficiency and a limit of 30 ng/mL (75 nmol/L) to define vitamin D insufficiency in adults. In the paediatric population, the consensus is less obvious and we consider that a serum concentration of minimum 20 ng/mL is necessary. A study on more than 200 children from Lyon, followed in the paediatric nephrology unit and having a renal function normal or sub-normal, demonstrated an important prevalence of vitamin D deficiency (75%) in adolescents and pre-adolescents. Concurrently, the appearance of new bone imaging techniques (especially high-resolution peripheral quantitative computed tomography HR-pQCT) improved bone status evaluation in a non-invasive manner. Given the new pathophysiological data on pleiotropic role of vitamin D (bone, cardiovascular system, adipose tissue) and given the proportion of French children possibly suffering from vitamin D deficiency, it seems urgent to actualize current recommendations regarding systematic supplementation in vitamin D. This transversal study on 200 healthy children and adolescents will allow to have an overview of vitamin D status in French healthy children and adolescents, studying with non-invasive, safe, reliable and innovative tools, the theoretical targets of vitamin D (bones, cardiovascular system and nutritional status); and then to lay the foundations of therapeutic trials aiming to evaluate the mode of vitamin D supplementation for healthy children and adolescents; while having a cohort for HR-pQCT measurements, that will allow us to have French reference range in a 10-17 year-old population, for this innovative, non-invasive and low radiation exposure technique.
Detailed description
To study the correlation between bone assessment by high-resolution peripheral quantitative computed tomography (HR-pQCT) and vitamin D serum concentration.
Interventions
OTHERExploration of Vitamin D roles
* Visit 1: questioning, physical examination, blood sampling (including plasma collection for future genetic analyses), carotid ultrasound * Visit 2 (same day as visit 1 or maxi 3 months later): HR-pQCT, dual energy x-ray absorptiometry (DXA), iontophoresis of acetylcholine and sodium nitroprusside
Sponsors
Hospices Civils de Lyon
Study design
Allocation
NA
Intervention model
SINGLE_GROUP
Primary purpose
HEALTH_SERVICES_RESEARCH
Masking
NONE
Eligibility
Sex/Gender
ALL
Age
10 Years to 17 Years
Healthy volunteers
Yes
Inclusion criteria
* 10 year-old \<or= Age \< 18 year-old * Without mobility handicap (medical walker, crutch, wheelchair…) * Written informed consent (signed by parents)
Exclusion criteria
* History of treatment with growth hormone * History of treatment with oral corticoids, taken over more than 3 consecutive months * Current treatment with growth hormone, corticoids or anti-calcineurin * Treatment with aspirin or nonsteroidal anti-inflammatory drug within the last three weeks * Treatment with paracetamol within the last week * Chronic pathology with an impact on growth: * Parenteral nutrition * Chronic inflammatory disease (rheumatologic or digestive notably) * System diseases (lupus, granulomatosis, vascularitis) * Renal failure * Diabetes * Serious intercurrent disease (infection, neoplasia) * Ongoing pregnancy * Patient unaffiliated with the French universal healthcare system.
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| To study the correlation between the results of bone microarchitecture obtained by high-resolution peripheral quantitative computed tomography (HR-pQCT) and vitamin D serum concentration. | up to 3 months | The HR-pQCT evaluates bones down to the level of the tiny individual elements that nature configures in a way that makes bones as strong as possible. HR-pQCT measures bone density and quantifies the three dimensional geometry, strength and microarchitecture of bone at the lower arm (radius) and lower leg (tibia). |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Values and standard deviation of 25-OH vitamin D3 plasma concentration concentration in the population studied. | Once. At inclusion (V1). | Blood intake. |
| To study the correlation between vitamin D plasma concentration and nutritional and pubertal status, cardiovascular status, inflammatory status . | up to 3 months | Nutritional and pubertal status will be assessed thanks to: Body Mass Index, Dual-energy X-ray Absorptiometry, adipokines level. Cardiovascular status will be assessed thanks to arterial pressure, Intima-media Thickness (IMT), Extra-media Thickness (EMT), lipid profile, endothelial function. IMT and EMT will be obtained using carotid ultrasound. Endothelial function will be evaluated following a protocol of iontophoresis of acetylcholine and sodium nitroprusside. Inflammatory status will be measured looking at C-reactive protein plasma level. |
| To evaluate the relation between bone parameters (HR-pQCT) and adipokines; and the relation between bone parameters and cardio-vascular data (blood pressure, IMT, EMT, lipid profile, endothelial function). | up to 3 months | — |
Countries
France
Outcome results
None listed