Objective:

To prospectively examine the association between intake of B vitamins and the risk of death among individuals with Parkinson’s disease (PD).

Background:

Folate and vitamins B6 and B12 have been proposed as protective against the development of PD. Whether intake of these vitamins prior to or after disease diagnosis could reduce the risk of death among PD patients is unknown.

Design/Methods:

The study population comprised 714 women from the Nurses’ Health Study and 801 men from the Health Professionals Follow-up Study who were newly diagnosed with PD during follow-up. Total intakes of folate, vitamin B6, and vitamin B12 were repeatedly assessed using a validated food frequency questionnaire. Mortality was ascertained via the National Death Index and state vital statistics records. For each vitamin, we fitted Cox regression models to estimate the hazard ratio (HR) and 95% confidence interval (CI) of death from all causes according to quartiles of cumulative average intakes.

Results:

We documented 973 deaths over 32 to 34 years of follow-up. A higher total intake of folate, vitamin B6, and vitamin B12 after PD diagnosis was not associated with a lower risk of death from all causes. In contrast, a lower risk of death was observed among those with a higher intake of these vitamins before PD diagnosis. The pooled hazard ratio comparing extreme quartiles of intake was 0.58 (95% CI:0.44-0.77; p-trend <0.001) for folate, 0.77 (95% CI:0.58-1.01; p-trend= 0.11) for B6, and 0.80 (95% CI: 0.64-1.01; p-trend=0.003) for B12. These associations appeared to be driven by intakes from supplemental sources.

Conclusions:

The results of our study suggest that higher intakes of B vitamins before, but not after, disease diagnosis decrease the risk of death among individuals with PD.