A new research has indicated that patients with a recent onset of Parkinson disease have a high prevalence of vitamin D insufficiency, but vitamin D concentrations do not appear to decline during the progression of the disease.
"Vitamin D insufficiency has been reported to be more common in patients with Parkinson disease (PD) than in healthy control subjects, but it is not clear whether having a chronic disease causing reduced mobility contributes to this relatively high prevalence," wrote the authors.
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 PD, diagnosed within five years of entry into the study.
They conducted a survey study of vitamin D status in stored blood samples from patients with PD who were enrolled in the placebo group of the Deprenyl and Tocopherol Antioxidative Therapy of Parkinsonism (DATATOP) trial.
The authors found a high prevalence of vitamin D insufficiency and deficiency in 157 study participants with early, untreated PD. At the baseline visit, most study participants (69.4 percent) had vitamin D insufficiency and more than a quarter (26.1 percent) had vitamin D deficiency.
"At the end point/final visit, these percentages fell to 51.6 percent and 7 percent, respectively."
"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," wrote the authors.
"These findings are consistent with the possibility that long-term insufficiency is present before the clinical manifestations of PD and may play a role in the pathogenesis of PD," concluded the authors.
The report has been published in Archives of Neurology, one of the JAMA/Archives journals.