Association of Vitamin B12 and Folate Deficiency with Vasovagal Syncope: A Case-Control Study.

HIGHLIGHTS: Vitamin B12 and folate status were evaluated in adults with vasovagal syncope.No association was found between vitamin deficiency and vasovagal syncope overall.Lower vitamin B12 levels were observed in patients with frequent syncope.

BACKGROUND

Clinical evidence suggests an association between vitamin B12 deficiency and vasovagal syncope (VVS) in pediatric patients. This study investigated the association of vitamin B12 and folate deficiency with VVS in adults.

METHODS

In this case-control study, adult patients with VVS who presented to the tertiary syncope unit for head-up tilt table testing comprised the case group. Age- and sex-matched individuals without syncope history from the population-based Tehran Cohort Study served as the control group. Exclusion criteria included but were not limited to the use of vitamin B supplements, carbamazepine, or phenobarbital, and sleeve gastrectomy. Serum vitamin B12, folate, and homocysteine levels were measured and compared.

RESULTS

From February 2020 through February 2021, 44 patients comprised the case group, matched with 44 controls (mean age, 37.9 years; 23 [52.3%] females in each group). No statistically significant difference existed between the groups in vitamin B12 or folate deficiency or serum levels. Serum vitamin B12 levels were significantly lower in patients with frequent VVS (≥3 lifetime episodes) than in patients with infrequent VVS (<3 lifetime episodes) (233.8 [80.7] vs 305.2 [118.1] pg/mL; P=0.042), and the association remained significant after adjustment for confounders (P=0.026).

CONCLUSION

No association existed between vitamin B12 or folate deficiency or serum levels and VVS. Frequent VVS was associated with lower serum vitamin B12 levels than infrequent VVS.