Clinical efficacy of vitamin D combined with conventional therapy for sudden sensorineural hearing loss in patients with vitamin D deficiency: a randomized controlled trial.

Objective: This study aimed to evaluate whether adjunctive vitamin D supplementation enhances the efficacy of conventional therapy in treating sudden sensorineural hearing loss (SSNHL) in patients with vitamin D deficiency, and to assess both short-term and long-term clinical outcomes.

Methods: In this prospective randomized controlled trial, 101 SSNHL inpatients with vitamin D deficiency (serum 25-hydroxyvitamin D < 75 nmol/L) were enrolled at Yinchuan First People's Hospital (January-December 2024). Participants were randomized into a control group (n = 51, receiving conventional therapy: methylprednisolone and ginkgo biloba extract) and an experimental group (n = 50, conventional therapy + oral vitamin D3 [1500-2000 IU/day] for 10 days). Hearing and tinnitus outcomes were assessed via pure tone audiometry (PTA) and the Tinnitus Handicap Inventory (THI) at baseline, 10 days, and 3 months.

Results: Baseline characteristics were comparable between groups (all P > 0.05). At 10 days, the experimental group demonstrated significantly higher total effective rates for hearing recovery (82.0% vs. 52.9%, P < 0.001) and tinnitus improvement (83.3% vs. 71.1%, P = 0.007) compared to the control group. Mean PTA improvement was 29.3 dB HL vs. 14.2 dB HL (P < 0.001). At 3 months, the experimental group maintained significantly better outcomes, with a mean PTA improvement of 25.1 dB HL versus 12.5 dB HL in the control group (P < 0.001) and a greater reduction in THI scores (27.5 vs. 13.9, P < 0.001). The total effective rate for hearing remained superior in the experimental group (76.0% vs. 47.1%, P = 0.002).

Conclusion: Vitamin D supplementation combined with conventional therapy significantly improves both short-term and sustained long-term hearing and tinnitus outcomes in SSNHL patients with vitamin D deficiency. These findings support its role as a safe and effective adjuvant treatment, warranting further validation through multicenter trials.