Indication: Hearing loss

Source: Ann Intern Med, January 2, 2007;146(1):63-4.

Research:
Seven hundred and twenty-eight older Dutch men and women showing signs of hearing loss were randomly assigned to receive either 800 micrograms of folic acid or a placebo daily for three years.

Results:
At the end of the trial, researchers found that the ability to hear low-frequency sound did not decrease significantly in those taking folic acid supplements. After three years, thresholds of the low frequencies increased by 1.0 decibel in the folic acid group and by 1.7 decibels in the placebo group. But there was no slowing the de-cline in hearing high frequencies in either group. Researchers noted that folic acid fortification of food was prohibited in The Netherlands during the study, so baseline folate levels in participants were about half of those found in the U.S. population. They concluded that folic acid supplementation slowed the decline in hearing of the speech frequencies associated with aging in a population from a country without folic acid fortification of food, therefore the effects seen in the study warrant further confirmation, especially in populations from countries with folic acid fortification programs.