Low Vitamin D Levels May Raise Parkinson’s Disease Risk

Previous studies have reported that lower blood levels of Vitamin D (measured as serum 25-hydroxyvitamin D) are observed people with Parkinson's Disease, as compared to healthy counterparts. Paul Knekt, from the National Institute for Health and Welfare in Helsinki (Finland), and colleagues studied whether serum vitamin D level are predicative of the risk of Parkinson’s.  The team assessed 3,175 men and women, ages 50 to 79 years, who did not have Parkinson’s Disease at the study’s start.  The subjects were followed for a 29-year period, during which the incidence of Parkinson’s was tracked. The researchers determined serum 25-hydroxyvitamin D level from frozen blood samples stored at the study’s start, and used a mathematical model to estimate the relationship between serum vitamin D concentration and Parkinson disease incidence. Individuals with higher serum vitamin D concentrations showed a reduced risk of Parkinson disease. After adjustment for confounding factors, the relative risk of Parkinson's disease between the highest and lowest quartiles of serum 25-hydroxyvitamin D levels was 0.33. The team concludes that: “The results are consistent with the suggestion that high vitamin D status provides protection against Parkinson disease.”