Low Serum Vitamin D is Not Associated with an Increase in Mortality in Oldest Old Subjects: The Octabaix Three-Year Follow-Up Study

Background: Poor vitamin D status, i.e. low serum levels of 25-hydroxyvitamin D [25(OH)D], is common in the general population. Prospective epidemiologic data on the association between vitamin D and mortality in oldest old subjects are limited. Objective: This study aimed to determine whether 25(OH)D concentrations were prospectively and independently associated with cardiovascular disease (CVD) mortality and all-cause mortality in oldest old subjects. Methods: A total of 312 subjects aged 85 years old at baseline (Octabaix study) were followed for 3 years. Sociodemographic and overall geriatric assessment data were collected. Serum 25(OH)D concentrations were used to assess vitamin D status. Data on overall and cardiovascular mortality were collected. Results: The mean serum 25(OH)D levels were 28 ± 30 ng/ml. During the follow-up period, 58 subjects (18.5%) died. Twenty-five of the deaths (8%) were related to CVD. There were no differences in mortality rates according to the different quartiles of vitamin D (p = 0.41 for total mortality and p = 0.86 for CVD mortality). Conclusion: In community-dwelling oldest old subjects, serum 25(OH)D levels were not associated with overall or CVD mortality after a 3-year follow-up.