Mov Disord. 2013 Apr 2. doi: 10.1002/mds.25405. [Epub ahead of print]
The relationship between balance control and vitamin D in Parkinson's disease-a pilot study.
Peterson AL, Mancini M, Horak FB.
Source
Parkinson's Center of Oregon, Oregon Health and Science University, Portland, Oregon, USA; Parkinson's Disease Research and Education Center, Portland Veterans Affairs Hospital, Portland, Oregon, USA.
Abstract
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. © 2013 Movement Disorder Society.
Copyright © 2013 Movement Disorder Society.
PMID: 23554003 [PubMed - as supplied by publisher]

(I am unable to assess if this study is meaningful. Not enough information about the trial. Though studies in elderly with low Vit D levels and increased incidence of falls gives me much pause.)