Vitamin D May Reduce Parkinson's Disease Risk
The sunshine vitamin appears to shine a favorable light on the risk of Parkinson’s disease, according to a new study. High blood levels of vitamin D may reduce the chances of developing this neurological disease.
An estimated 1 to 1.5 million people in the United States have Parkinson’s disease, a chronic, progressive movement disorder whose cause is unknown. Thus far a cure has been elusive, but medications and surgery can help manage the symptoms, which can include rigidity or stiffness of the limbs and trunk, slowness of movement (bradykinesia), impaired balance and coordination, and tremor of hands, arms, legs, jaw, and face.
Researchers at the National Institute for Health and Welfare in Helsinki evaluated data from 3,173 men and women aged 50 to 79, and followed up over 29 years. During that time they documented 50 cases of Parkinson’s disease. Individuals who had the lowest levels of vitamin D were three times more likely to develop Parkinson’s when compared to study participants who had the highest levels.
Parkinson’s disease occurs when cells in an area of the brain called the substantia nigra malfunction and die. These cells produce dopamine, a chemical that sends signals to the areas of the brain that control movement and coordination. As the dopamine-producing cells die and the level of the chemical declines, the affected individual becomes unable to control his or her movements in a normal way.
Previous research has indicated that the substantia nigra contains high levels of vitamin D receptors, which suggests this vitamin has an important role in maintaining the normal function of the cells in this area of the brain.
The study’s authors point out that although they do not know the exact role vitamin D plays in Parkinson’s disease, the vitamin’s antioxidant properties could be a factor, as well as its ability to regulate calcium levels, detoxify the body, enhance conduction of electricity through nerve cells, or modulate the immune system. Vitamin D deficiency has been linked with rheumatoid arthritis, preeclampsia, bone and heart health, asthma, and other health risks.
In an editorial that accompanied the study, which was published in the Archives of Neurology, Marian Leslie Evatt, MD, MS, from Emory University in Atlanta, said the study’s results were “the first promising human data to suggest that inadequate vitamin D status is associated with the risk of developing Parkinson’s disease.” Further research is necessary to identify the exact role and other factors in the relationship between vitamin D and Parkinson’s.
Knekt P et al. Archives of Neurology 2010; 67(7): 808-11
Parkinson’s Disease Foundation