Vitamin D Supplementation and the Immune Response

The main objective is to assess the variation in plasma levels of cathelicidin before and after influenza vaccination. All bibliographic data suggests that supplementation vitamin D in the elderly often deficient in this vitamin may have a double interest: * By induction of cathelicidin, assist in anti-infective response in particular to the influenza virus * The normalization of vitamin D status, promote the return to an appropriate immune response limiting excess inflammation and improving capacity to respond. The entire project will collect new information on the merits of the use of vitamin D in aging. A better knowledge of mechanisms involved and the impact of aging on them is a necessary prerequisite the definition of a new strategy using this drug in the elderly particularly fragile in order to improve its autonomy. This definition seems a sociological interest obvious economic knowing the current aging population and its impact future of our health system.

Inclusion Criteria: \- Aged 65 or over subject, * Subjects with a vitamin D levels below 30 ng / ml, * Acceptance of vitamin D (100 000 IU of UVEDOSE ®) * Acceptance of influenza vaccination with INTANZA15 ® * Affiliation to a social security scheme * The subject agrees not to change their eating habits Exclusion Criteria: * Liver disease: cirrhosis, chronic hepatitis. * Renal impairment whatever degree * Hypercalcemia (serum calcium\> 2.6 mol / l) * Hypo-or hyperparathyroidism history, history of renal colic. * Disease / acute infection, moderate or severe (at the discretion of the investigator) on the day of vaccination or febrile illness (temperature ≥ 38 ° C). The subject should not be included in the study as his condition is not cured or her fever has not gone down). * Long-term treatment with bisphosphonates, corticosteroids, anti-inflammatory, anticonvulsant, antiepileptics, fibrates. * Known hypersensitivity to vitamin D * Prior supplementation (in the last year) or supplementation of vitamin D during * Participation at the time of inclusion in the trial, or planned participation during the same period that this trial, another trial on a vaccine, drug, medical device. * Vaccination during the 4 weeks prior to vaccination or immunization of the test set out in the three weeks after vaccination test. * Transfusion of immunoglobulins, blood or blood products during the last 3 months * Congenital or acquired, known or suspected immunodeficiency, immunosuppressive therapy in the last 6 months, such as cancer chemotherapy or radiotherapy; steroids long-term systemic (prednisone or equivalent for more than two consecutive weeks in the Previous 3 months). * Systemic Hypersensitivity to any component of the vaccine (ovalbumin, chicken protein, neomycin, formaldehyde, octoxinol 9), or a history of reaction to influenza vaccine or a vaccine containing one of the substances in the vaccine trial, which involved life-threatening. * Deprivation of liberty or by administrative order issued by a court, subject to emergency medical or involuntary hospitalization. * Topic enjoying a measure of legal protection (guardianship, guardianship ...).