Hypovitaminosis D Prediction Score (SCOPYD)

Vitamin D has effects on many tissues, and hypovitaminosis D is frequent. In a French survey conducted among 1587 adults, vitamin D insufficiency (<30ng/ml) has been reported in 80% of subjects, including 43% with moderate deficiency (<20ng/ml) and 5% with severe deficiency (<10ng/ml). Because of the possible consequences of hypovitaminosis D (osteomalacia in adults…), the number of vitamin D determination has increased ten-fold since 2005 in France, reaching 4.5 million € in 2011, and with it the costs for health insurance. However, there is currently no consensus on the strategy for detection, diagnosis and treatment of hypovitaminosis D. We propose to develop a predictive clinical score of hypovitaminosis D based on the accurate assessment of solar exposure, vitamin D intakes and hypovitaminosis D risk factors collected through a self-administered questionnaire.

The 2500 subjects included in this unique arm will complete a self-administered questionnaire and will have a blood sampling to measure vitamin D blood concentration.

Vitamin D determination will be carried out for each center in a single laboratory by chemiluminescence technique. Vitamin D determination is the gold standard for the development and validation phases of the score. It will define the variables of the self-administered questionnaire to be included in the final score (development phase) and be the gold standard in the evaluation of the performance score (validation phase). The blood sample will be collected after the completion of the questionnaire, on the same day.

The ability of the score to classify adults in one of these three categories: Category 1 : Vitamin D sufficiency (≥30 ng/ml) Category 2 : Hypovitaminosis D between 30 and 10 ng/ml Vitamin D insufficiency (<30 ng/ml) Vitamin D deficiency (<20 ng/ml) Category 3 : Severe deficiency (<10 ng/ml)

Inclusion Criteria: - Men and women aged 18 to 70 years old Exclusion Criteria: Participation in a study related to vitamin D Taking at least 80 000 IU vitamin D in the last 3 months as a single dose Pregnancy or breast-feeding Renal failure : severe renal impairment, dialysis, having kidney transplant Known hepatic impairment Gastrointestinal disorders: Celiac disease, Crohn's disease, ulcerative colitis, bariatric surgery, gastrointestinal surgery with stoma Known primary hypo/hyperparathyroidism Bone cancer/metastases current or in the last 2 years Treatment with antiepileptics Long-term treatment with glucocorticoids (> 3 months) Treatment with antiretroviral Legal incapacity or limited legal capacity Non-recipient of French Social Security