Evaluating the Effect of Alpha-Lipoic Acid and B Vitamins (B1, B6, B9, and B12) on the Improvement of Post-Thyroidectomy Dysphonia: A Randomized Double-Blind Placebo-Controlled Clinical Trial.

BACKGROUND

Post-thyroidectomy dysphonia is a common complication, often resulting from transient laryngeal nerve dysfunction, intubation-related trauma, and postoperative inflammation. Nutritional supplementation with alpha-lipoic acid (ALA) and B vitamins has been proposed to support neural recovery, reduce oxidative stress, and inflammation. This randomized clinical trial aimed to evaluate the expected anti-inflammatory effects of such supplementation in improving micro-ischemia/thrombosis affecting nerve function that may lead to post-thyroidectomy dysphonia as a result of manipulations during surgery.

METHODS

In this double-blind, placebo-controlled trial, 85 patients who developed dysphonia post-thyroidectomy were randomized to receive either a daily oral supplement containing ALA and B vitamins (n = 42) or a placebo (n = 43) for 14 days postoperatively. Primary outcomes were changes in the voice handicap index-10 (VHI-10) and VHI-30 total and subdomain scores. Secondary outcomes included serum C-reactive protein (CRP) levels and prevalence of dysphagia. Subgroup analyses were performed for patients with benign and malignant thyroid pathology.

RESULTS

Baseline demographic and clinical characteristics were comparable between groups. After 14 days, both groups showed significant improvements in VHI-10 and VHI-30 scores (P value < 0.001 within groups). The mean change in VHI-10 was 7.5 ± 6.48 in the supplement group and 7.88 ± 7.67 in the placebo group (P value 0.8 between groups). VHI-30 subdomains improved significantly within groups but not between groups. Median CRP decreased significantly in both groups (P value 0.03 and P value 0.004), with no significant between-group difference (P value 0.26). Swallowing difficulty prevalence declined in both groups without statistical significance. In the subgroup with malignant etiology, the supplement group showed greater improvement in VHI-30 total score, physical, and emotional subscales compared to placebo (P value 0.03, 0.01, and 0.03, respectively).

CONCLUSION

Supplementation with ALA and B-complex vitamins was associated with improvements in VHI scores after thyroidectomy among patients with malignant pathology. While overall between-group differences were not statistically significant, the observed subgroup effect supports further investigation into micronutrient-based neuroprotective strategies for postoperative vocal rehabilitation.