Low Levels of Vitamin B12 in Parkinson’s Contributes to Disability

Those with the lowest B12 levels performed worse on cognitive and motor outcomes.

CHICAGO — Low levels of vitamin B12 are known to be linked to neuropathy and cognitive impairment in advanced Parkinson’s disease, however it’s not clear how B12 status in early Parkinson’s affects disease progression and disability.

In order to examine the effects of B12 status in early Parkinson’s, Chadwick Christine, MD, of the University of California, San Francisco, and colleagues measured baseline B12 levels in 680 baseline serum samples from patients with early, untreated Parkinson’s disease. Motor and cognitive assessments were conducted at baseline and again at follow-up. Findings from the study were presented at the American Neurological Association 2015 Annual Meeting in Chicago.

 At baseline, 12.8% of participants had a B12 level <184 pmol, and 5% had B12 levels <152 pmol. Those in the lowest B12 tercile (<234 pmol) showed greater morbidity and performed worse on some cognitive and motor outcomes as measured by Unified Parkinson’s Disease Rating Scale and postural instability gait difficulty. Overall, one in eight Parkinson’s patients had low B12 status.

The researchers concluded that low B12 status may be a risk factor for greater morbidity in Parkinson’s, and efforts to prevent or correct the deficiency should be undertaken to possibly slow the onset of disability in Parkinson’s disease.


  1. Christine C et al. Abstract S411. Presented at: American Neurological Association Annual Meeting 2015. September 27-29, 2015; Chicago.