CRP and vitamin D deficiency: Multifactorial logistic regression analysis showed that disease duration, neutrophils, lymphocytes, C-reactive protein (CRP), ferritin, and vitamin D deficiency were independent risk factors for the diagnosis of BPPV (OR>1, p < 0.05), monocyte count was an independent protective factor for the diagnosis of BPPV (OR<1, p < 0.05), and the area under curve (AUC) was 0.927.