Age, race and season predict vitamin D status in African American and white octogenarians and centenarians.

OBJECTIVE: Poor vitamin D status has been associated with osteoporosis, falls, cardiovascular diseases, cancer, autoimmune diseases, pain, nursing home placement, and other age-related conditions, but little is known about the prevalence and predictors of vitamin D status in those aged 80 and older. Thus, this study tested the hypothesis that vitamin D status would be 1) poorer in a population-based multi-ethnic sample of centenarians as compared with octogenarians and 2) predicted by specific dietary, demographic or environmental factors.
DESIGN: Cross-sectional population-based analyses.
SETTING: Northern Georgia in the United States. PARTICIPANTS: Men and women aged 80 to 89 (octogenarians, n=80) and 98 and older (centenarians, n=237). MEASUREMENTS: Regression analyses were used to examine the associations of serum 25-hydroxyvitamin D [25(OH)D] with age, gender, race, living arrangements, dairy food intake, supplement intake, and season.
RESULTS: The prevalence of vitamin D insufficiency [25(OH)D<50 nmol/L] was higher in centenarians than in octogenarians (p<0.02). In logistic regression analyses, the risk of being vitamin D insufficient was significantly increased by being a centenarian vs. octogenarian (p<0.005) and by being African American vs. white (p<0.001) and decreased by taking a supplement with vitamin D (p<0.001) or by having vitamin D status measured in the summer or fall (each p<0.05), compared with spring.
CONCLUSIONS: Centenarians and octogenarians are at high risk for vitamin D insufficiency for many of the same reasons identified in younger populations. Given the numerous potential adverse consequences of poor vitamin D status, efforts are needed to ensure vitamin D adequacy in these older adults.