2.1. Setting and Sample

Follow-up study done in the context of Alexandros (Active Life Expectancy, Aging and Disorders Related to Obesity Study) after a mean follow up of 9078 person/years (mean 9.59 ± 3.5, min 5.0 max 15.0), a cohort study of community-dwelling people 60 years and older living in Santiago, Chile, previously described [28]. Briefly Alexandros is a longitudinal study of people ≥ 60 years that includes three cohorts of different demographic origin and socioeconomic status: (a) 1173 Subjects born before 1940 recruited in the frame of The SABE study [29] (in 1999–2000 through a probabilistic sampling), (b) 950 people born between 1940–1948 recruited between 2005 and 2008, randomly selected from 28 Public Primary healthcare center registries and (c) 266 people of high socio-economic status, born before 1949, randomly selected from the private health insurance system registries and recruited in 2007. After approval by the Institutional Scientific Ethics Review Board of the Institute of Nutrition and Food Technology (INTA) of the University of Chile (Acta n°23, 2012, Fondecyt n°1130947), and informed consent signature, biomedical, sociodemographic, anthropometric, and functional evaluations were performed, and a fasting blood sample was obtained. The Inclusion criteria for this study was individuals with measurements of vitamin D Levels at baseline and Cognitive Function (MMSE short form) evaluation. The exclusion criteria were having a MMSE short form score < 13 The sample consisted of 955 participants (69.7% women) 60 years and older followed since its recruitment.