Vitamin D Deficiency and the Risk of Recurrent Benign Paroxysmal Positional Vertigo.

Background Benign paroxysmal positional vertigo (BPPV) is the most common cause of positional vertigo. It is a short-lived (seconds) rotatory attack of vertigo in relation to the position of the head. Vitamin D deficiency may be one of the causes leading to BPPV. As there is no relevant local study from Iraq, this study aimed to evaluate the association between BPPV and vitamin D deficiency. Methodology This retrospective, case-control study was conducted at the otolaryngology clinic of Al-Ramadi Teaching Hospital during a 26-month duration. The study included 40 patients clinically diagnosed with BPPV and 80 individuals as controls. Detailed information regarding the demographic and clinical characteristics was obtained from each participant. Serum vitamin D and calcium levels were measured for each participant. Results Both cases and controls were matched regarding age and gender. Serum vitamin D level in cases (15.458 ± 6.14 ng/mL) was lower than controls (23.604 ± 12.58 ng/mL), with a p-value of 0.0001 and large clinical effect size (0.8). Vitamin D deficiency was found in 35 cases and 37 controls, with a highly significant difference (p = 0.0001) and an odds ratio of 8.135. Vitamin D deficiency in BPPV patients with recurrence (12.615 ± 4.096 ng/mL) was lower than those without recurrence (18.3 ± 6.611 ng/mL), with a highly significant difference (p = 0.002) and small clinical effect size (0.3). Older age and vitamin D deficiency were risk factors for recurrence according to the multinominal logistic regression test (p < 0.05). Conclusions Vitamin D deficiency might cause the occurrence and recurrence of BPPV. Older age might be a risk factor for BPPV recurrence.