Yang B, Lu Y, Xing D, et al. - In this systematic review and meta-analysis of observational studies, researchers intended to determine if there is an association between serum vitamin D levels and benign paroxysmal positional vertigo (BPPV). In total, 18 studies were included. Findings suggested an association of BPPV with reduced levels of serum Vitamin D. Subgroup analysis by geographical area demonstrated that the level of vitamin D in BPPV was significantly lower than in controls in China, but not outside China. Across all countries in the sample, vitamin D levels were significantly lower in recurrent than non-recurrent BPPV. Vitamin D deficiency has emerged as an independent BPPV risk factor.