Evaluation Of The Effect Of L. Casei DG® On Vitamin D Absorption In Patients Under Vitamin D Supplementation.

Inclusion Criteria: 1. Male and female adults aged ≥ 18 and ≤ 60 years; 2. Middle East Area residency; 3. Serum levels of Vit. D≤ 20 ng/ml at screening, for which a course of Vitamin D at a dose of 4.000 U.I. daily has been prescribed as per clinical practice; 4. Body Mass Index (BMI) between 18,50 and 29,99; 5. Acceptance of the study by the patient and written informed consent to participate in the study provided. Exclusion Criteria: 1. Serum level of Vit. D \> 20ng/ml; 2. Documented malabsorption of Vit. D and/or other oligoelements and vitamins; 3. BMI ≤ 18.5 and ≥29,99; 4. Hypersensitivity to cholecalciferol or to any of the excipients of the prescribed drug; 5. Contraindications to Vit. D supplementation (e.g. hypercalcemia, hypercalciuria, renal failure); 6. Vit. D therapy or prophylaxis within 30 days before the enrolment in this study; 7. History of administration of systemic antibiotics or antibiotics at bowel action (es: rifaximin) within 30 days before the enrolment in this study; 8. History of administration of probiotics, prebiotics, (including probiotic/prebiotic enriched foods) within 30 days before the enrolment in this study; 9. Present treatment with Proton Pump Inhibitors (PPIs) and aluminium-containing antacids; 10. Present treatment with drugs interfering on the absorption of Vit. D, as barbiturates, antiepileptics (i.e. phenobarbital, phenytoin, carbamazepine), corticosteroids, antimycotics (i.e. ketoconazole, fluconazole), anti-retroviral agents, cholestyramine, colestipol, orlistat; 11. Patients with certain or suspected diagnosis of chronic inflammatory bowel diseases, cystic fibrosis or mucoviscidosis; 12. Patients with hepatic impairment (Alanine transaminase (ALT) or Aspartate aminotransferase (AST)\>3 times the upper limit of normal); 13. Patients with nephrolithiasis or nephrocalcinosis; 14. Infective gastro-intestinal syndromes in active phase or gastro-intestinal infectious residue which can alter the bowel absorption on the judgement of the investigator; 15. Episodes of viral or bacterial enteritis within 2 months before the enrolment in the study; 16. History or presence of gastric and/or duodenal ulcers; 17. Psychiatric syndromes and/or psychological disturbances; 18. Any severe pathology which could interfere with the study treatment; 19. Presence of any relevant severe condition or clinically relevant abnormal laboratory parameters that in the opinion of the investigator may interfere with the participation to the study; 20. Poor reliability or presence of conditions leading to a poor compliance/adherence to the protocol by the patient; 21. Active malignancy of any type, or history of a malignancy (patients with a history of other malignancies that have been surgically removed and who have no evidence of recurrence for at least five years before study enrolment are also acceptable); 22. Pregnancy and/or breastfeeding\*; 23. Existence of mental illness or any mental condition potentially interfering with appropriate compliance with protocol procedures; 24. Patients without self-judgement ability; 25. Participation in another investigational study or treatment with any investigational drug within the previous 30 days; 26. Recent history or suspicion of alcohol abuse or drug addiction; 27. Patients not compliant with the procedures of the protocol.