Serum vitamin D levels and mortality in Mexicans: results from the Mexican Health and Aging Study.

Background: the population in Latin America is aging and elders face several obstacles for good health, including an elevated frequency of vitamin D deficiency. Thus, identification of patients at high risk to develop its negative consequences should be a priority. Objective: the objective of this analysis was to determine if levels of vitamin D lower than 15 ng/ml are associated with high mortality in Mexican elderly population, from the database of the Mexican Health and Aging Study (MHAS). Methods: prospective, population study in Mexico, that included Subjects of 50 years and older who were evaluated for Serum vitamin D levels during the year 2012 (third wave of the study). Serum 25(OH)D levels were categorized into four groups, based on cutoff points used in previous studies on vitamin D and frailty: < 15, 15-< 20, 20-< 30 and ≥ 30 ng/ml. Mortality was evaluated during 2015 (fourth wave of the study). Hazard ratio was calculated (for mortality) through Cox Regression Model, adjusted for covariates. Results: we included 1626 participants, and those with lower levels of vitamin D were older, more often women, required more aid for activities of daily living, reported higher number of chronic diseases, and lower scores on cognition. The relative risk of death was 5.421 (95 % CI 2.465-11.92, p < 0.001) for the participants with vitamin D levels < 15, which after adjusting for covariates, remained statistically significant. Conclusions: levels of vitamin D lower of 15, are associated with an increase in the rate of mortality in community-dwelling senior Mexicans.