PhD Scientific Days 2025

Poster Session III. - R: Neurosciences

The Relationship Between Vitamin B12 Levels and Resting-State Functional MRI Brain Connectivity

Name of the presenter

Váraljai Christopher

Institute/workplace of the presenter

Department of Neurointervention and Neurosurgery - Semmelweis University

Authors

Váraljai Christopher¹, Prof. Dr. Kamondi Anita¹, Dr. Berente Dalida Borbála PhD¹, Dr. Horváth András Attila PhD², Bolla Gergő²

1: Department of Neurointervention and Neurosurgery - Semmelweis University
2: Neurocognitive Research Centre - Nyírő Gyula National Institute for Psychiatry and Addictology

Text of the abstract

The Relationship Between Vitamin B12 Levels and Resting-State Functional MRI Brain Connectivity
Introduction:
Vitamin B12 deficiency affects the nervous system, including brain connectivity and cognition. If detected early, these changes can be reversed by vitamin B12 supplementation. The current lower limit of the vitamin B12 normal range was set not to prevent neurological symptoms but to prevent megaloblastic anaemia.
Objective:
To determine whether the lower limit of vitamin B12 is set at an ideal level for neurological involvement. In addition, to investigate the effect of vitamin B12 deficiency on brain functional connectivity.
Methods:
We studied 86 patients who underwent neuropsychological testing and resting-state functional magnetic resonance imaging (fMRI). Their vitamin B12 levels were measured and standardised. Three parameters were calculated from the fMRI scans: LCOR, IC, and fALFF.
Results:
The higher a patient's vitamin B12 level, the faster they completed the trailmaking test B (TMT-B), and the higher their total score on the Addenbrooke's cognitive test (ACE) was. This association plateaued 40% above the current clinical lower limit of vitamin B12 levels. In patients whose vitamin B12 levels were less than the lower limit +40%, their vitamin B12 levels significantly correlated (linear regression) with their TMT-B score (p=0.007), their ACE total score (p=0.016), and their ACE memory score (p=0.023).
In the same patients, there was a significant correlation between fMRI parameters of several brain regions and patients' vitamin B12 levels (linear regression). fALFF parameter showed a significant correlation with vitamin B12 levels in a significant proportion of Default Mode Network (DMN) regions.
Discussion:
Cognitive performance correlated significantly with vitamin B12 levels that were above the current lower limit of the vitamin B12 level, indicating deficiency status. The decrease in total ACE score is mainly explained by a decrease in memory performance. Differences in fMRI measured in regions involved in DMN explain the memory involvement. Based on our results, an increase of the lower limit of vitamin B12 by 40% should be considered.