Vitamin B12-B6-folate treatment improves blood-brain barrier function in patients with hyperhomocysteinaemia and mild cognitive impairment.
Level 4 - case-series / case-control
Uncontrolled before-and-after interventional study without a concurrent control group
PubMed 12826740 · doi:10.1159/000071002
What was done
Thirty patients with mild cognitive impairment and elevated serum homocysteine (with normal baseline B12 and folate levels) were treated orally with a high-dose vitamin B12-B6-folate combination for an average of 270 days. Cerebrospinal fluid (CSF) tau protein and CSF/serum albumin ratio (an indicator of blood-brain barrier integrity) were measured before and after treatment, and baseline albumin ratios were compared against age-matched controls.
What was found
Serum homocysteine levels normalized following supplementation. The albumin ratio, which was higher in patients than age-matched controls at baseline and correlated with vascular risk factors, was significantly reduced after treatment (no exact numbers or p-values reported in the abstract). CSF-tau levels showed a non-significant numeric decline. No patients progressed to dementia during the 270-day follow-up.
Why it matters
This study provides preliminary evidence that blood-brain barrier dysfunction associated with hyperhomocysteinemia in mild cognitive impairment may be partially reversible with B-vitamin supplementation.
Limits
The study lacked a randomized control or placebo group, making it impossible to separate treatment effects from spontaneous variation or regression to the mean. The sample size was small (n = 30), the abstract provides no numerical data or confidence intervals, and cognitive outcomes were assessed only as gross progression to dementia rather than via detailed psychometric testing.
Cited by
- partial In people with high homocysteine, treatment with a combination of vitamin B6, vitamin B12, and folate improved cognition and reduced blood-brain barrier permeability.