Evaluation of vitamin D metabolism in patients with bilateral sensorineural hearing loss.

The possible role of vitamin D in hearing impairment was investigated by the measurement of three metabolites of vitamin D in 28 patients with bilateral sensorineural hearing loss (BSNHL). Twenty-three of 28 patients showed a significantly decreased level of 1,25-dihydroxyvitamin D3, with a normal value of 25-hydroxyvitamin D3. In addition to experimental and clinical reports regarding vitamin D deficiency, the present study suggests that vitamin D deficiency is one of the etiologies of BSNHL, through the calcium metabolism and microcirculation in the cochlea.