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.