Vitamin B6 intake before Parkinson's diagnosis and risk of death
What it found
In 1,521 people with Parkinson's disease, higher intake of vitamin B6 and folate before diagnosis was linked to a lower risk of death.
Intake after diagnosis showed no link.
What they found
Studies in people
Death risk before diagnosis
People with the highest average intake of vitamin B6 before diagnosis were less likely to die than those with the lowest intake. The same pattern was seen for folate, but not for vitamin B12.
Survival time
Those in the top intake group for folate lived a median of 12.6 years after diagnosis, compared with 11.2 years for the bottom group. For vitamin B6, median survival was 12.5 years versus 10.9 years.
Supplements vs food
The link with lower death risk was stronger when the vitamins came from supplements, especially for vitamin B12.
Intake after diagnosis
Taking these B vitamins after being diagnosed with Parkinson's disease was not linked to how long people lived.
Timing of intake
The link was strongest for intakes reported 12 to 16 years before diagnosis, when the disease may have been at an early stage.
What the authors conclude
“Higher intake of B vitamins before disease diagnosis, particularly folate and vitamin B6, may decrease the risk of death in individuals with PD.”
Also in their conclusions
- They conclude that higher intake of B vitamins before disease diagnosis, particularly folate and vitamin B6, may decrease the risk of death in individuals with Parkinson's disease.
- They state that postdiagnosis intake did not appear to impact survival.
- They suggest that B vitamins, which are inexpensive, safe, and easy to administer, could be considered as potential interventions in clinical trials for people at risk.
How it was done
There are no treatments that can slow Parkinson's disease, and damage may already be substantial by the time symptoms appear. The authors wanted to see whether B vitamins, which have shown protective effects in lab studies, affect survival when consumed before and after diagnosis.
They followed 1,521 people from two large groups who developed Parkinson's disease, using diet questionnaires repeated for up to 30 years before and more than 10 years after diagnosis. They recorded 1,005 deaths over 15 years and compared death rates across intake levels of folate, vitamin B6, and vitamin B12.
What it can’t tell you
- This was an observational study, so it can show a link but cannot prove that B vitamins directly cause longer survival.
- The study included mostly White health professionals with relatively good nutrition, so the results may not apply to other groups.
- The authors could not account for disease progression, symptoms, or blood levels of B vitamins, which might affect the results.
Who paid
- Funding
- Funded by NINDS NIH HHS; NCI NIH HHS (from the PubMed record).
- Conflicts
- Conflicts of Interest and Disclosure. M. Flores-Torres, X. Zhang, C. Christine, K. Bjornevik, A. Hung, M. Schwarzschild, and A. Ascherio report no relevant disclosures related to this manuscript.
- Authors work at
- Brigham and Women's Hospital and Harvard Medical School, USA; Harvard T.H. Chan School of Public Health, USA; University of California San Francisco, USA
The paper
- Title
- Intake of Folate, Vitamin B6, and Vitamin B12 Before and After Disease Diagnosis and the Risk of Death in Individuals with Parkinson's Disease
- Type
- Study
- Evidence
- Studies in people
- Summarised from
- Full text
- Cite
- Zhang X, Flores-Torres MH, Christine CW, et al (2026). Intake of Folate, Vitamin B6, and Vitamin B12 Before and After Disease Diagnosis and the Risk of Death in Individuals with Parkinson's Disease. Movement disorders. doi:10.1002/mds.70178Free full textPubMed 41524297DOI
Summary written 26 Sep 2026. Check it against the paper before it changes what you eat. How we summarise papers · Report an error