The relationship between balance control and vitamin D in Parkinson's disease-a pilot study

Background: Balance problems and falls are a major source of morbidity and mortality in patients with Parkinson's disease. Vitamin D supplementation reduces falls and sway in neurologically intact elderly fallers, but effects in Parkinson's disease are not established. Methods: To study this relationship and select outcome measures for a vitamin D intervention study, balance function and vitamin D concentration were quantified in a series of Parkinson's patients in a cross-sectional, observational study. Participants underwent a battery of 5 balance tests. Results: Serum vitamin D concentrations were correlated inversely with Parkinson's severity, as measured by the motor Unified Parkinson's Disease Rating Scale. Among the balance measures, vitamin D concentrations were correlated with automatic posture responses to backwards translation, specifically with response strength and stance weight asymmetry. Conclusions: These findings support the hypothesis that vitamin D plays a role in balance among patients with Parkinson's disease and identify specific outcome measures for detecting effects of vitamin D upon balance.