B12 and Folic Acid for Alzheimer's: Does it Help?

observational-study PMID: 34101780

Quick Summary: A study found that taking vitamin B12 and folic acid supplements for 6 months improved thinking skills and reduced inflammation in people with Alzheimer's disease.

What The Research Found

Researchers looked at how vitamin B12 and folic acid affect people with Alzheimer's. They found that taking these supplements daily for six months helped improve:

Thinking skills: Like memory and focus.

Reduced inflammation: This is linked to brain health.

Study Details

Who was studied: 101 people with Alzheimer's disease.

How long: The study lasted for 6 months.

What they took: Participants took either a daily dose of folic acid (1.2 mg) and vitamin B12 (50 μg) or a placebo (a dummy pill).

What This Means For You

If you have Alzheimer's or are concerned about brain health, this research suggests that taking vitamin B12 and folic acid might help. Talk to your doctor before starting any new supplements. They can help you figure out the right dosage and if it's safe for you.

Important Note: This study was done in a place where food isn't fortified with folic acid. The results might be different if you live in a place where folic acid is added to foods.

Study Limitations

It's important to remember:

The study only looked at the effects for 6 months.

The study was "single-blinded," meaning only the participants didn't know if they were getting the real supplement or the placebo.

The study was done in a specific area, so the results might not be the same for everyone.

The study didn't check if people were already low in B12 or folic acid before the study.

Key Findings

The study found that daily supplementation with folic acid (1.2 mg) and vitamin B12 (50 μg) for 6 months improved cognitive performance and reduced inflammation in patients with probable Alzheimer’s disease (AD). Significant improvements were observed in Montreal Cognitive Assessment (MoCA) total scores, naming, orientation, and attention domains (ADAS-Cog). Supplementation also increased plasma S-adenosylmethionine (SAM) and the SAM/SAH ratio, while decreasing homocysteine (Hcy), S-adenosylhomocysteine (SAH), and tumor necrosis factor-alpha (TNFα). These results suggest that combined B12 and folic acid may benefit AD patients, particularly in regions without folic acid-fortified diets.

Study Design

This was a randomized, single-blind, placebo-controlled trial conducted at Tianjin Key Laboratory of Cerebrovascular and Neurodegenerative Diseases. The study enrolled 120 participants with clinically diagnosed probable AD (stable condition) and analyzed data from 101 completers (51 intervention, 50 placebo). Cognitive function, metabolite levels (SAM, SAH, Hcy), and inflammatory markers (TNFα) were measured at baseline and 6 months. Linear mixed models for repeated measures were used to analyze outcomes.

Dosage & Administration

Participants received folic acid 1.2 mg/day + vitamin B12 50 μg/day orally. The intervention group was compared to a placebo group over 6 months.

Results & Efficacy

Cognitive Improvement:
MoCA total scores: P = 0.029
MoCA naming scores: P = 0.013
MoCA orientation scores: P = 0.004
ADAS-Cog attention domain: P = 0.008
Metabolite Changes:
Plasma SAM increased: P < 0.001
SAM/SAH ratio increased: P < 0.001
Serum Hcy decreased: P < 0.001
Plasma SAH decreased: P < 0.001
Inflammation Reduction:
Serum TNFα decreased: P < 0.001

All outcomes were statistically significant, indicating the intervention positively influenced cognition and inflammation biomarkers.

Limitations

Single-blinding: Only participants were blinded, potentially introducing performance bias.
Population specificity: Participants were from a non-folic acid-fortified region (Tianjin, China), limiting generalizability to populations with routine folate fortification.
Short duration: 6 months may not capture long-term effects or disease progression.
No baseline B12/folate deficiency data: Efficacy in patients with normal B12/folate levels is unclear.
Mechanistic gaps: The study did not explore direct links between metabolite changes and cognitive outcomes.

Future research should assess longer-term supplementation, diverse demographics, and mechanisms underlying the observed effects.

Clinical Relevance

For AD patients in regions without folic acid fortification, combining high-dose folic acid (1.2 mg/day) and vitamin B12 (50 μg/day) may enhance cognitive function (e.g., attention, orientation) and reduce inflammation. However, the lack of baseline deficiency data raises questions about efficacy in non-deficient individuals. The doses exceed dietary reference intakes (DRI: 400 μg folic acid, 2.4 μg B12), warranting caution for long-term use. Clinicians might consider targeted supplementation for AD patients with low folate/B12 status, while public health strategies could prioritize folate fortification to amplify B12’s benefits. Further trials are needed to validate these findings in broader populations.

Analysis based on the provided study summary. Always consult a healthcare provider before initiating supplementation.