Effect of Vitamin D on Cognitive Decline of Patients With Memory Complaint

Pre-Inclusion Criteria : * Patients aged 60 years or older, * Who report to a memory centre with symptoms of memory complaint, * Having a Mini-Mental State Examination (MMSE) score strictly \> the 5th percentile for sociocultural level of the patient (GRECO standards for elderly patients), * Having visual, hearing abilities (authorized equipment) and an oral or written expression sufficient for the suitable realization of the tests, * Who accept participation in the study and are able to sign the informed consent of the - Affiliated to the French social security system. Inclusion Criteria: * Insufficient 25 OH D serum level : 25 OH D \< 50 nmol/L (20 ng/ml), * Normal corrected plasma calcium concentration, * Normal kidney function (cockcroft \> 30 mL/mn) Exclusion Criteria: * Alzheimer's disease or other dementia, * Parkinson's disease treated, * Epilepsy treated, * Huntington's disease, * Brain tumor, * History of a progressive disease which may have consequences for the central nervous system (blood pressure, higher or equal to 180/100 mmHg, chronic pulmonary disease with hypoxia; cerebrovascular accident of less than 3 months, cranial traumatism with persistent neurologic deficit, subdural hematoma, brain surgery), * Antecedent of alcoholism or chronic drug-addiction with an obvious or documented consequence on cognition, * Severe depression : score Montgomery Asberg Depression Rating Scale (MADRS) \> 18, * Psychotropic drug therapy (at the discretion of the clinician), * Hypercalcaemia or treatment for a hypercalcaemia, * Known hypersensitivity to the vitamin D, * Granulomatous disease, * Treatment of vit D at doses higher than the current recommendations, * History of calcium urinary lithiasis of less than 1 year, * Nonsteroidal antiinflammatory drug (NSAID) chronic treatment, * Severe medical or surgical affection of less than 3 months, * Unstable health, severe hepatic or renal deficiency, * Deprivation of liberty, under judicial protection, * Institutionalization (EHPAD), * Illiteracy, * Participation in another biomedical research. A diagnosis of MCI (Mild Cognitive Impairment) of less than 6 months is not a criterion of non-inclusion.