A new study on vitamin D levels and Parkinson's disease risk points to the need for further research on whether vitamin D supplements can protect against the movement disorder, according to an editorial in the July 2010 issue of Archives of Neurology.
The author of the editorial is Marian Evatt, MD, assistant professor of neurology at Emory University School of Medicine and director of the Atlanta Veterans Affairs Medical Center's Movement Disorders Clinic.
The study, also reported in Archives of Neurology, is the first to show that low vitamin D levels can help predict whether someone will later develop Parkinson's disease. Researchers at Finland's National Institute for Health and Welfare measured vitamin D levels from more than 3000 people, using blood samples taken between 1978 and 1980, and then followed those people to see whether they developed Parkinson's. People with the lowest levels of vitamin D were three times more likely to develop Parkinson's, compared to the group with the highest levels.
This report by itself does not prove a causal relationship where low vitamin D boosts Parkinson's risk. Other causal chains are possible. For example, it is possible some of the same genetic variants that cause differences in blood vitamin D level also separately cause changes in neuronal or immune system function and thereby change Parkinson's risk.
Vitamin D might provide protection by protecting dopaminergic neurons from toxins.
Research on animals suggests that vitamin D may protect neurons that produce dopamine from toxins. Besides vitamin D levels, factors such as genetics and exposure to pesticides also are associated with the risk for developing Parkinson's disease.
This report brings to mind a long studied link between multiple sclerosis and vitamin D. For example, a Canadian study found low vitamin D is linked to higher MS risk, MS is thought to be an auto-immune disorder, and vitamin D is thought to play a role modulating immune function. Curiously, a report in March 2010 found ultraviolet light might reduce the damage from MS independent of UV's stimulation of skin vitamin D synthesis. However, at least one study has found that vitamin D supplements appear to cut risk of MS relapse.
|Share |||Randall Parker, 2010 July 12 10:52 PM Brain Disorders|