DISCUSSION
In this case-control study from a tertiary referral hospital and a
population-based cohort, we found no remarkable difference in vitamin
B12 or folate deficiency, or their serum levels between adult patients
with VVS and controls; nonetheless, patients with frequent VVS are more
likely to have lower serum levels of vitamin B12 compared to patients
with infrequent VVS. Moreover, the prevalence of vitamin B12 deficiency
is possibly higher in patients with frequent VVS compared to patients
with infrequent VVS, albeit statistically non-significant, may be of
clinical significance.