Effects of Vitamin D in Parkinson's Disease (PD)

The proposed study is a randomized, double-blinded, placebo controlled intervention trial to
measure the effects of vitamin D at (10,000IU/day) versus placebo on balance and falls in
Parkinson's disease. The investigators will measure static, dynamic, and ambulatory balance,
as well as strength, falls, and cognition before and after 16 weeks of therapy. Dynamic
posturography will be used to measure static and ambulatory balance, a device called
iMOBILITY will measure a timed up and go, and strength will be measured with the Biodex
machine checking knee flexion and extension. Multiple quality of life and cognitive tests
will also be performed.

Inclusion Criteria:

- Parkinson's disease;

- ability to ambulate 50 feet;

- ability to cooperate with balance testing;

- vitamin D level less than 40ng/ml;

- balance problems;

- ability to walk 50 feet without the help of another person

Exclusion Criteria:

- MMSE < 25;

- another neurological or orthopedic deficit that in the examiner's opinion would
affect testing;

- history of renal stones or hypercalcemia;

- unwillingness to not be on other vitamin D supplementation during the study