Objectives: To elucidate the mechanism through which vitamin D is associated with decreased falls.
Design: This was a convenience sample from a larger observational study examining correlations between vitamin D and 1) falls, 2) motor function, and 3) cognition (n=159).
Setting: Falls data were collected via weekly on-line surveys completed in the participants' homes. Yearly evaluations of motor and cognitive function were conducted in an out-patient setting of a large tertiary medical center.
Participants: Participants from the Intelligent Systems for Assessment of Aging Changes Study (ISAAC), a community-based cohort study of independently living older adults over age 70, who had vitamin D concentration within 6 months of clinical evaluations were included in the analysis.
Results: Participants mean age was 85 years and 74% were women. Fallers (n=37) had significantly lower vitamin D concentration (32.9ng/ml) compared to non-fallers (39.2ng/ml) (p<0.01). The relationship between vitamin D and falls remained significant after adjusting for age, health status (via CIRS), and supplement use (p=0.004). Vitamin D concentration were significantly associated with cognitive impairment (Clinical Dementia Rating = 0.5) (p=0.02) and MMSE (p<0.01) after adjusting for age, gender, and education. Vitamin D concentrations did not correlate with any motor measures.
Conclusion: Vitamin D concentrations correlated with cognition and falls, but not with motor measures. Further research is needed to demonstrate a causal relationship between vitamin D and cognitive function and determine if cognition plays a role in falls reduction.