ATLANTA, March 16 (UPI) -- Patients with early Parkinson's had a high prevalence of vitamin D insufficiency but vitamin D did not decline with disease progression, U.S. researchers say.
Dr. Marian L. Evatt of Emory University School of Medicine and the Atlanta Veterans Affairs Medical Center and colleagues examined the prevalence of vitamin D insufficiency in untreated patients with early Parkinson's disease diagnosed within five years of entry into the study.
The researchers examined the vitamin D status in stored blood samples from patients with Parkinson's disease who were enrolled in the placebo group of the Deprenyl and Tocopherol Antioxidative Therapy of Parkinson trial.
The study authors found a high prevalence of vitamin D insufficiency and deficiency in 157 study participants with early, untreated Parkinson's disease. At the baseline visit, 69 percent had vitamin D insufficiency and 26 percent had vitamin D deficiency.
"At the end point/final visit, these percentages fell to 51.6 percent and 7 percent, respectively," the researchers say in a statement. "Contrary to our expectation that vitamin D levels might decrease over time because of disease-related inactivity and reduced sun exposure, vitamin D levels increased over the study period."
The findings, published in the Archives of Neurology, are consistent with the possibility that long-term insufficiency is present before the clinical manifestations of Parkinson's disease and may play a role in the development of Parkinson's.