Association of Vitamin B12 and Folate Deficiency with Vasovagal Syncope:
A Case-Control Study
Abstract
Aims: There is some clinical evidence of the association
between vitamin B12 deficiency and vasovagal syncope (VVS) in pediatric
patients. We aimed to investigate the possible association of vitamin
B12 and folate deficiency with VVS in adults. Methods: In this
case-control study, we included adult patients with VVS who presented to
our tertiary syncope unit for a head-up tilt table test as the case
group. We selected age- and sex-matched individuals without any history
of syncope from the population-based Tehran Cohort Study as the control
group. The exclusion criteria included but were not restricted to taking
vitamin B supplements, carbamazepine, or phenobarbital, and sleeve
gastrectomy. We measured and compared serum levels of vitamin B12,
folate, and homocysteine. Results: From February 2020 to
February 2021, we included 44 patients in the case group, matched with
44 controls, with a mean age of 37.9 years and 23 (52.3%) females in
each group. There was no statistically significant difference between
the study groups regarding vitamin B12 or folate deficiency, or their
serum levels. The serum level of vitamin B12 was remarkably lower in
patients with frequent VVS (≥3 lifetime episodes) compared to patients
with infrequent VVS (<3 lifetime episodes) [233.8 (80.7)
versus 305.2 (118.1) pg/mL; P=0.042] and this association remained
significant after adjustment for possible confounders (P=0.026).
Conclusion: We found no association between vitamin B12 or
folate deficiency, or their serum levels and VVS; nevertheless, frequent
VVS, compared to infrequent VVS, was associated with a lower serum
vitamin B12.