Predictive Questionnaire for Vitamin D Insufficiency in Healthy Adults

Study Overview
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Brief Summary
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The purpose of this clinical study is to evaluate the metrological properties of a questionnaire that aims to identify the vitamin D status in reference to a vitamin D blood dosage.

Detailed Description
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Each subject will perform only one visit (visit V1). The study duration per subject will last about 2 hours. During this visit V1, the subjects will perform a medical exam in order to check their eligibility (general statement and check of inclusion / non-inclusion criteria). The eligible subjects will fill up a study questionnaire and will perform a blood sampling for a dosage of serum vitamin D.

Official Title
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A Study to Validate a Predictive Questionnaire for Vitamin D Insufficiency in Healthy Adults

Conditions
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Healthy Volunteers

Intervention / Treatment
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* Procedure: Blood sampling
* Other: Predictive questionnaire for vitamin D insufficiency


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Male and female volunteers Subject able to communicate with the investigator and the study team, able to read and write and follow all study instructions. Written informed consent provided and signed prior screening, after receiving and understanding the subject information. Registered with the French Social Security, in agreement with the French law on biomedical experimentation. Exclusion Criteria: Subject with diagnosed osteoporosis, osteopenia or osteomalacia. Subject with known disease that contributes in osteoporosis: Rheumatoid arthritis, Malabsorption syndrome, Inflammatory bowel disease, Hyperthyroidism, Hyperparathyroidism. Subject with known hepatic impairment. Subject with known liver impairment or with a history of renal transplantation. Subject with history of cancer. Subject with history of bariatric surgery. Subject taking or having taken osteoporosis inducing treatment, or treatment with an effect on calcium and phosphorus metabolism during the 3 months prior the visit: Corticosteroids, Enzyme inducing anticonvulsants, Heparin. Subject requiring vitamin D supplementation for a diagnosed pathology. Pregnant or breastfeeding Female. Subject with history of alcohol or drug abuse. Participation to any other clinical trial simultaneously and/or not having ended the exclusion period of another clinical trial. Subject of legal age unable of giving consent. Subject deprived of liberty by judicial or administrative decision. Subject of legal age under legal protection. Subject having received over 4500 Euros for clinical trial participation within the prior year including the indemnity for the present study.

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 65 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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Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| All subjects<br>300 eligible subjects will perform a blood sampling for a dosage of serum vitamin D and will fill up a study questionnaire during one visit. | Procedure: Blood sampling<br>* One blood sampling will be performed for a serum vitamin D dosage. The volume of blood collected will not exceed 4 ml.<br>Other: Predictive questionnaire for vitamin D insufficiency<br>* The questionnaire includes 19 questions concerning the following topics : a) sun exposure, b) living situation, c) eating habits and Vitamin D dietary intakes. In addition, two questions will capture demographic data.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Questionnaire internal validity | Evaluation of the internal coherence and factorial structure of the questionnaire, establishment of scoring rules | Day 1 | 
| Questionnaire external validity | Prediction of the vitamin D status (threshold value, sensitivity, specificity for vitamin D insufficiency; threshold value, sensitivity, specificity for vitamin D deficiency) | Day 1 | 
| Confounding factors (demographic data) | Interests for coupling the study questionnaire and demographic data (age, gender, Body Mass Index, phototype). | Day 1 | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Vitamin D, Vitamin D Deficiency, Vitamin D Insufficiency, Healthy adults, Predictive questionnaire