Research published in Otolaryngology–Head and Neck Surgery (2010; 143(6):826–830) examined the relationship between serum folate levels and age-related hearing loss in 60 adults.
The researchers found that individuals with hearing loss had significantly lower serum folate levels. In addition, there was an inverse association between serum folate concentration and the degree of high-frequency hearing loss, meaning lower folate levels were associated with poorer high-frequency hearing.