Is there any link between vitamin D deficiency and vasovagal syncope?

BACKGROUND: This study aimed to investigate serum 25[OH]D levels between patients with vasovagal syncope (VVS) diagnosed with head‐up tilt table test (HUTT) and age‐matched healthy people. METHODS: The study included 75 consecutive patients (32.3 ± 10.7 years), who presented with syncope and underwent HUTT and 52 healthy controls (32.9 ± 14.1 years). HUTT patients were divided into two groups according to whether there was syncope response to the test. Patients underwent cardiac, psychiatric, and neurological investigation. Serum 25[OH]D levels were measured by chemiluminescent microparticle immunoassay method. RESULTS: There was no difference between the two groups in terms of age, gender, body mass index (BMI), echocardiographic findings (P > .05). Mean serum 25[OH]D (24.5 ± 6.3 vs 20.1 ± 8.8 ng/mL, P = .003) and vitamin B12 levels (436.4 ± 199.2 vs 363.1 ± 107.6 pg/mL, P = .009) was lower in syncope patients when compared to the control group. In correlation analyses, syncope was shown as correlated with the vitamin D (r = −264, P = .003) and vitamin B12 levels (r = −233, P = .009). But, multivariate regression analyses showed that only vitamin D increased risk of syncope [OR: 0.946, 95% CI (0.901‐0.994)]. There was no difference in terms of age, gender, BMI, echocardiographic findings between the in HUTT positive (n = 45) and negative groups (n = 29). Only vitamin D level was significantly lower in HUTT positive group (17.5 ± 7.7 vs 24.4 ± 9.1 ng/mL, P = .002). There was no difference among in the vasovagal subgroups in terms of vitamin D level and other features. CONCLUSION: Vitamin D and B12 levels were reasonably low in syncope patients, but especially low Vitamin D levels were associated with VVS diagnosed in HUTT.