Iranian Journal of Otorhinolaryngology

Iranian Journal of Otorhinolaryngology

Association between Serum Vitamin B12 and Sensorineural Hearing Loss: A Case-Control Study

Document Type : Original

Authors
Nimra Tabassum 1
Gangadhara Somayaji 1
Nayana V G 1
Shubham Sukerndeo Upadhyay 2
shwetha shetty 3
1 Department of Otorhinolaryngology, Yenepoya Medical College, Deralakatte, Mangalore Dakshina Kannada, Karnataka, India.
2 Senior Research fellow Centre for Systems Biology and Molecular Medicine, Yenepoya Research Centre Yenepoya University Deralakatte, Mangalore.
3 Senior Project officer, Centre for Health Informatic and Evidence Based Medicine, Yenepoya University, Deralakatte, Mangalore Dakshina Kannada, Karnataka, India. karnataka
10.22038/ijorl.2026.96570.4177
Abstract
Introduction:
The latest evidence from systematic reviews and meta-analyses indicates that nutritional intake and dietary habits are not only associated with an individual’s health but also influence hearing function through complex biological mechanisms. Vitamin B12 plays a role in neuronal function, myelin synthesis, and cellular metabolism. Previous studies have suggested a possible association between vitamin B12 deficiency and hearing impairment; however, the evidence remains inconclusive. This study aimed to compare serum vitamin B12 levels in adults with sensorineural hearing loss (SNHL) and individuals with normal hearing and to evaluate the association between vitamin B12 levels and audiometric parameters.

Materials and Methods:
A case-control study was conducted among 102 participants, comprising 51 patients with SNHL and 51 healthy controls. Serum Vitamin B12 levels and audiometric parameters were compared between the two groups. An additional exploratory Receiver Operating Characteristic (ROC) curve analysis was performed to assess the discriminative ability of serum B12 levels in the study sample.

Results:
The mean serum vitamin B12 was 6465.16-± 5493.20 pg/ml in the SNHL group and 9154.98 ± 6151.63 pg/ml in the control group. The serum Vitamin B12 level in patients with sensorineural hearing loss was significantly lower than that in the control group (p=0.022). Exploratory ROC analysis demonstrated an area under the curve of 0.64 (95% CI: 0.531-0.748).

Conclusion:
Participants with sensorineural hearing loss (SNHL) had lower serum B12 levels compared to the control group. These findings indicate an association between serum vitamin B12 levels and sensorineural hearing loss (SNHL). However, the modest discriminatory performance and the observational case-control design do not warrant the use of serum vitamin B12 as a reliable diagnostic or predictive marker. Larger prospective studies incorporating relevant clinical and metabolic confounders are required to clarify this association.
Keywords
Vitamin B12
Hearing Loss
SNHL
ROC curve
pure tone audiometry.
Subjects
1.                   Guo Z, Ji W, Song P, Zhao J, Yan M, Zou X, et al. Global, regional, and national burden of hearing loss in children and adolescents, 1990-2021: a systematic analysis from the Global Burden of Disease Study 2021. BMC Public Health. 2024 Sep 16;24(1):2521. doi:10.1186/s12889-024-20010-0.
2.                   Zhou P, Wu H, Xu K, Pan X, Li L. The global burden of age-related hearing loss among individuals aged 60 years and older: an analysis for the Global Burden of Disease Study 2021 and predictions to 2050. PLoS One. 2026 Jan 16;21(1). doi:10.1371/journal.pone.0340498.
3.                   Moreno-Herraiz N, Bohn L, Otero-Luis I, Cavero-Redondo I, Zornoza-González E, Escobar-Molina A, et al. Association between cardiovascular risk factors and hearing loss, including sudden sensorineural hearing loss: an umbrella review of systematic reviews and meta-analyses. Appl Sci (Basel). 2026 Mar 19;16(6):2951. doi:10. 3390/ app16062951.
4.                   World Health Organization. Deafness and hearing loss [Internet]. [cited 2026 May 30]. Available from: https://www.who.int/news-room/ fact-sheets/detail/deafness-and-hearing-loss
5.                   Centers for Disease Control and Prevention. Data and statistics about hearing loss in children [Internet]. [cited 2026 May 30]. Available from: https://www.cdc.gov/hearing-loss-children/ data/ index. html
6.                   Pang X, Zhang X, Xu D, Bu C, Qiu Y, Feng P, et al. Bioactive hydrogels for the reconstruction of sensorineural hearing loss. Bioact Mater. 2026 Feb;56:160-180. doi:10. 1016/j. bioactmat. 2025. 09.014.
7.                   Anastasiadou S, Al Khalili Y. Hearing loss. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2026 Jan-. [Updated 2023 May 23].
8.                   Shen Y, Zhou T, Zou W, Zhang J, Yan S, Ye H, et al. Global, regional, and national burden of hearing loss from 1990 to 2021: findings from the 2021 Global Burden of Disease Study. Ann Med. 2025 Jul 3;57(1):2527367. doi:10.1080/ 07853890. 2025.2527367.
9.                   Jung SY, Kim SH, Yeo SG. Association of nutritional factors with hearing loss. Nutrients. 2019 Feb 1;11(2):307. doi:10.3390/nu11020307.
10.                He H, Han Z, Cheng S, Zhou Y. Hearing the call of mitochondria: insight into its role in sensorineural hearing loss. Neurobiol Dis. 2025 Sep;213:107030. doi:10.1016/j.nbd.2025.107030.
11.                Xu B, Huang Y, Yu D, Chen Y. Advancements of ROS-based biomaterials for sensorineural hearing loss therapy. Biomaterials. 2025 May;316:123026. doi:10.1016/j.biomaterials.2024.123026.
12.                Lu W, Tang R, Jiahui X, Shipeng Z, Tao G, Hanyua W, et al. Protective effects of dietary nutrients on hearing loss: a systematic review and meta-analysis. Front Nutr. 2025 May 9;12:1528771. doi:10.3389/fnut.2025.1528771.
13.                Rodrigues J, Anand S, Gunjawate DR, Kumar K, Ravi R. Exploring the intricate connection between vitamin B12 deficiency and hearing loss: a systematic literature review. Ear Nose Throat J. 2026 Feb;105(2). doi:10.1177/ 014556 132 412 98 070.
14.                Naik S, Fedosov SN, Mahalle N, Narawade S, Nexo E, Heegaard CW. High oral doses of vitamin B12 in early pregnancy improve B12 status of mother and child irrespective of subsequent supplementation: a longitudinal study in B12-insufficient Indian women supplemented with either milk, vitamin pills, or placebo. Biochimie. 2026 Jan 30(26)00023-4. doi:10.1016/j.biochi.2026.01.014.
15.                Prasad R, Aroor R, Menon M, Shetty S, Saldanha M, Kalam A. Serum methylcobalamin, folic acid, and homocysteine levels and their association with sensorineural hearing loss. Indian J Otol. 2025 Jan;31(1):23-28. doi:10.4103/ indianjotol. indianjotol_180_24.
16.                Karli R, Gül A, Uğur B. Effect of vitamin B12 deficiency on otoacoustic emissions. Acta Otorhinolaryngol Ital. 2013 Aug;33(4):243-247.
17.                Rodrigues J, Anand S, Gunjawate DR, Kumar K, Ravi R. Exploring the intricate connection between vitamin B12 deficiency and hearing loss: a systematic literature review. Ear Nose Throat J. 2026 Feb;105(2).doi:10.1177/01455613241298070.
18.                Kurioka T, Sano H, Furuki S, Yamashita T. Long-term administration of vitamin B12 and adenosine triphosphate for idiopathic sudden sensorineural hearing loss: a retrospective study. PeerJ. 2020 Dec 16;8. doi:10.7717/peerj.10406.
19.                Taha MS, Amir M, Mahmoud H, Omran A, Taha HM. Folic acid and vitamin B12 in idiopathic sensorineural hearing loss in children. Egypt J Otolaryngol. 2014;30(4):322-326. doi:10.4103/ 1012- 5574. 144964.
20.                Lasisi AO, Fehintola FA, Yusuf OB. Age-related hearing loss, vitamin B12, and folate in the elderly. Otolaryngol Head Neck Surg. 2010 Dec;143(6):826-830. doi:10.1016/j.otohns.2010.08.031.
21.                Akyay A, Soylu E, Ünsal S, Demirol H, Bahçeci S. Hearing status in vitamin B12-deficient children. J Paediatr Child Health. 2021 Jul;57(7):1060-1066. doi:10.1111/jpc.15392.
22.                Huang Y, Lv T, Xie M, He J, Pei J, Guan Y, et al. Blood homocysteine and folic acid levels may provide a reference value for the treatment of sudden total frequency deafness. Ann Palliat Med. 2019 Nov;8(5):604-610. doi:10.21037/apm.2019.10.08.
23.                Karaer I, Akalın Y. Low vitamin B12 level and vitamin D level adversely affect on cochlear health in women. Int J Vitam Nutr Res. 2020 Jun;90(3-4):333-338. doi:10.1024/0300-9831/a000616.
24.                Houston DK, Johnson MA, Nozza RJ, Gunter EW, Shea KJ, Satterfield S, et al. Age-related hearing loss, vitamin B-12, and folate in elderly women. Am J Clin Nutr. 1999 Mar;69(3):564-571. doi:10.1093/ajcn/69.3.564.
 
 
Iranian Journal of Otorhinolaryngology
Volume 38, Issue 6
November and December 2026
Pages 401-408