A recent meta-analysis published by the journal Nutrients found that both vitamin D supplementation and outdoor work are significantly associated with a reduced risk of developing Parkinson’s disease.
Parkinson’s disease (PD) is a progressive neurodegenerative disorder primarily effecting middle-aged and elderly individuals. PD is characterized by degeneration of the basal ganglia, a set of interconnected structures in the forebrain, and a deficiency of the neurotransmitter, dopamine. Both dopamine and basal ganglia are involved in cognition, memory and coordination of movement.
Individuals with PD may experience tremors, muscular rigidity and slow uncoordinated movement. Although the etiology behind PD is unclear, researchers agree that a combination of genetic and environmental factors contribute to the onset of PD.
In recent years, several studies have found that low vitamin D levels are associated with Parkinson’s disease. In the current meta-analysis, researchers aimed to determine whether vitamin D status, vitamin D supplementation or outdoor work may be associated with the risk for developing PD.
In order to evaluate the potential relationship between vitamin D and PD risk, the researchers analyzed data from 7 observational studies with a total of 5,690 PD patients and 21,251 matched controls. The studies investigated the relationship of vitamin D status, vitamin D supplementation or outdoor work with PD risk.
Was there a relationship between vitamin D and PD risk when compared with matched controls? Here is what the researchers found:
- Individuals who were vitamin D deficient (levels less than 20 ng/ml) had a two-fold increased risk of developing PD.
- Those who were vitamin D insufficient (levels less than 30ng/ml) experienced a 30% increased risk of PD.
- Vitamin D supplementation was associated with a 38% decreased risk of developing PD.
- Outdoor work was related to a 28% reduced risk for PD.
The researchers stated,
“In conclusion, based on the eligible studies we found that low vitamin D level was associated with increased risk of PD, which is consistent with the hypothesis that low vitamin D status is a risk factor for PD.”
“In addition, it was indicated that vitamin D supplementation and outdoor work may reduce PD risk. Thus, optimizing vitamin D level may represent a potential avenue for the prevention of PD.”
It is important to note that because the meta-analysis consisted of case control studies, the results only proved association, not causality. The researchers call for larger, well designed studies to further confirm the role of vitamin D in PD risk.