The idea of a link between inadequate vitamin A and hearing disorders was initially treated with suspicion, reflected by its being confined to animal studies and observations. But it was resurrected 11 years later, in 1949, by well-known New York ear-nose-throat expert M.J. Lobel, who treated 300 patients with progressive hearing loss by giving them 50,000 IU of vitamin A twice a week for six weeks. After the first six weeks, 83 per cent of patients responded positively. Lobel noted that progressive tinnitus improved dramatically and, in some patients, disappeared altogether.
His findings were confirmed by several subsequent studies and, in 1953, Hoffmann-La Roche published a major paper that established a definitive link between hearing problems and vitamin A deficiency.
Strangely, however, this work was never followed-up, and vitamin A therapy fell into disuse while pharmaceuticals have instead been used for inner-ear problems.
More recently, trials have suggested that the herb Ginkgo biloba can ease even severe cases of tinnitus, although an analysis found that five Ginkgo trials carried out so far were actually unscientific and flawed (Clin Otolaryngol, 1999; 24: 164-7).