Vitamin B<sub>12</sub> deficiency and Parkinson’s disease

Parkinson’s disease (PD) is a progressive neurodegenerative with various clinical manifestations, its origin not always can be explained only by dopamine deficiency. Long-term treatment levodopa (especially intraduodenal administration), as well manifestations of polyneuropathy, cognitive deficits, postural disorders freezing gate, REM sleep behavioral disorders, are more often associated vitamin B12 Several reasons for this association and mechanisms their development discussed. Early detection cobalamin deficiency in PD, especially patients from high-risk groups, makes it possible to stop pathological condition timely prevent irreversible changes. Modern data on the use high-dose (1000 μ g) oral presented, has comparable efficacy significant advantages, compared parenteral form, terms ease ability avoid undesirable postinjection reactions.