A study found that Folic Acid supplementation may prevent or slow age-related hearing loss. Age related hearing loss is the most common type of hearing loss, affecting approximately 10 million mature Americans.
The study followed 728 men and women in the Netherlands (where food is not fortified with folic acid). The study participants were given either 800 mcg of folic acid/day or a placebo from September 2000 to December 2004. Researchers found that folic acid supplementation slowed the decline of low frequency hearing in mature adults. Researchers believe this may be due in part because folic acid lowers homocysteine levels.
Durga, J. et al "Effects of Folic Acid Supplementation on Hearing in Older Adults", Annals of Internal Medicine, 2007;146:1-9.