Multidimensional Voice Profiles of Children With and Without Vitamin D Deficiency: A Pilot Cross-Sectional Comparative Study

Objectives: This study aims to compare multidimensional voice profiles of children aged 3-12 years with and without vitamin D deficiency in a pilot pediatric sample and to examine whether low vitamin D status is associated with measurable differences in perceptual, parent-reported, acoustic, and aerodynamic voice characteristics. Methods: This cross-sectional comparative study included 47 children who presented for routine pediatric evaluations at a private pediatric clinic in Adana, Türkiye. Participants were classified according to serum 25-hydroxyvitamin D [25(OH)D] levels as having vitamin D deficiency (< 20 ng/mL; n = 23) or normal vitamin D levels (≥ 20 ng/mL; n = 24). Voice assessment included the Turkish Pediatric Voice Handicap Index (pVHI), GRBAS scale, acoustic analysis of sustained /a/ including fundamental frequency, jitter, shimmer, harmonics-to-noise ratio (HNR), and cepstral peak prominence smoothed (CPPS), as well as maximum phonation time (MPT) and s/z ratio. Between-group comparisons were performed using independent-samples t tests or Mann-Whitney U tests, as appropriate. Age- and sex-adjusted sensitivity analyses were also conducted for parent-reported, acoustic, and aerodynamic outcomes. Results: In the primary unadjusted analyses, no statistically significant differences were found between children with vitamin D deficiency and those with normal vitamin D levels for any GRBAS parameter, including Grade, Roughness, Breathiness, Asthenia, and Strain (all P > 0.05). Similarly, pVHI functional, physical, emotional, and total scores did not differ significantly between groups (all P > 0.05). No significant between-group differences were observed for any acoustic or aerodynamic measure, including fundamental frequency, jitter, shimmer, HNR, CPPS /a/, connected speech CPPS, MPT, or s/z ratio (all P > 0.05). In age- and sex-adjusted sensitivity analyses, acoustic and aerodynamic outcomes remained nonsignificant, although an isolated adjusted difference was observed for the pVHI Emotional subscale. Conclusion: In this pediatric pilot sample, vitamin D deficiency was not associated with significant differences in primary multidimensional voice measures. These findings suggest that low vitamin D status may not produce overt voice impairment detectable by conventional perceptual, parent-reported, acoustic, and aerodynamic assessment in children, although subtle or domain-specific effects cannot be excluded. Larger age-stratified studies using more sensitive voice measures are needed.