Monthly Boluses Versus Daily Doses for Correcting Blood Vitamin D Deficit in Obese Children and Adolescents

Inclusion criteria

• Aged between 5 to 18 year-old
• Being obese (BMI >97th percentile, > IOTF 30, for age and gender using the WHO references)
• Patients (parents) having given their informed consent
• Patient having insurance from the national health system

Exclusion criteria

Children will be excluded from the study if:

• Symptomatic vitamin D deficiency (tetany, muscular hypotonia, hypocalcaemic seizure)
• Vitamin D supplementation in the 3 months preceding the inclusion visit (V1)
• Signs of rickets at the X-ray (osteopenia and cortical thinning of the long bones, stress fractures, and metaphyseal widening and fraying)
• Chronic disease such as granulomatous conditions, Williams syndrome, or hypothyroidism predisposing to hypocalcaemia or in case of hypercalcaemia (calcium > 2.65 mmol/L), liver/kidney disease, malabsorption diseases;
• Hypercalciuria (urinary Calcium/Creatinine > 0.7 mmol/mmol), calcium nephrolithiasis, hypervitaminosis D (25-(OH)D > 250 nmol/L); nephrocalcinosis;
• Ongoing treatment with anticonvulsants/barbiturates or steroids which increase the catabolism of 25(OH)D;
• Ongoing treatment with thiazides diuretics which reduce urinary excretion of calcium;
• Contraindications to the class of drugs under study, e.g. known hypersensitivity or allergy to class of drugs or the investigational product;
• Pregnancy, breastfeeding;
• Inability to follow the procedures of the study, e.g. due to language problems, psychological disorders, dementia, etc. of the participant;
• Simultaneous enrolment to another study which could influence the results of the current study;
• Patient under legal protection or deprived of liberty.