Higher Vitamin B12 Level at Parkinson's Disease Diagnosis Is Associated with Lower Risk of Future Dementia

Researchers employed a population-based cohort of subjects to explore the relationship between serum vitamin B12 at the time of Parkinson's Disease (PD) diagnosis and dementia risk, reports Physician's Weekly . Receiver operating curves were estimated for vitamin B12 cutoffs maximizing sensitivity and specificity for determining who developed dementia. People with PD who did not develop dementia had higher baseline levels of vitamin B12 at diagnosis compared to those who developed dementia. Dementia risk was significantly reduced in the third tertile compared with the second tertile, and skewed towards significance compared to the first tertile. Each 100-unit boost in vitamin B12 levels had a hazard ratio of 0.31 for future dementia, while a vitamin B12 cutoff of less than 587 ng/L was 87 percent sensitive and 70 percent specific in distinguishing subjects with dementia. PD sufferers with vitamin B12 levels lower than 587 ng/L were 5.4 times more likely to develop dementia, with half having dementia within five years of PD diagnosis versus 11 percent in those with a vitamin B12 level of 587 ng/L or higher. The researchers concluded that higher levels of serum vitamin B12 at PD diagnosis correlated with lower risk of future dementia.