Newly Diagnosed Parkinson Disease Patients Often Vitamin D Deficient
Vitamin D is an important nutrient for many body functions, from keeping bones strong to maintaining a healthy immune system. However, it is estimated that seven out of ten Americans are vitamin D deficient. Researchers are especially concerned about vitamin D status in neurodegenerative diseases, such as Parkinson’s, as the nutrient has an important role with maintaining normal function of cells in certain areas of the brain.
Vitamin D Insufficiency Commonly Found In Parkinson Patients
Parkinson’s disease (PD) belongs to a group of conditions called motor system disorders, which are the result of the loss of dopamine-producing brain cells in an area called the substantia nigra. Previous research has found that this section of the brain contains high levels of vitamin D receptors.
Marian L. Evatt MD MS of Emory University School of Medicine and the Atlanta Veterans Affairs Medical Center examined the prevalence of vitamin D insufficiency in untreated patients with early PD, diagnosed within five years of entry into the study. The team analyzed blood from stored samples of 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. At baseline, just over 69% of patients had vitamin D insufficiency, defined as 30-50 nmol/L. About 26% of patient had vitamin D deficiency, which is less than 30 nmol/L. 50nmol/L and above is generally considered adequate for overall health in most individuals, according to information by the National Institutes of Health.
However, the researchers note that vitamin D levels did not continue to decline, and in fact, improved slightly over the study period. At the final visit, 20 months later, these percentages fell to 51.6% and 7%, 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,” the authors write. “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.”
Vitamin D insufficiency is associated with a variety of clinical disorders and chronic diseases, according to background information presented in the article published in the Archives of Neurology. These include impaired balance, decreased muscle strength, and mood and cognitive dysfunction.
Lack of vitamin D has been reported to be more common in patients with Parkinson disease than in healthy control subjects. Still, it is not yet clear if the nutrient deficiency raises disease risk or if having high levels of vitamin is protective, says Dr. Evatt. “More research is needed to figure this out (but) there is certainly an association.”
Most people get the majority of vitamin D from sunlight exposure. Dietary sources include fish such as salmon and tuna and fortified dairy products.
Marian L. Evatt; Mahlon R. DeLong; Meena Kumari; Peggy Auinger; Michael P. McDermott; Vin Tangpricha; for the Parkinson Study Group DATATOP Investigators. High Prevalence of Hypovitaminosis D Status in Patients With Early Parkinson Disease. Arch Neurol, 2011; 68 (3): 314-319 DOI: 10.1001/archneurol.2011.30