Folate (Vitamin B9) for Hearing Changes

Folic acid slowed low-frequency hearing decline in older Dutch adults living without food fortification. The finding has not been replicated in fortified populations.

Overview

Folic acid slowed low-frequency hearing decline in older Dutch adults living without food fortification. The finding has not been replicated in fortified populations.

Verdict

Mixed evidence

One good trial in a folate-deplete population slowed hearing decline. Unlikely to help where dietary folate is already adequate.

How It Works

Folate lowers homocysteine, which is associated with impaired cochlear microvascular perfusion and oxidative injury to hair cells. Improved cochlear blood flow is the proposed route to slower decline.

Dosing & Protocol

Typical dose

Recommended dose: 400-800 mcg daily from food or supplement
Expected timeframe: The trial measured effects over three years. Nothing perceptible happens in weeks.

Protocol

form: Folic acid tablet or fortified food
duration: The supportive trial ran 3 years; short courses should not be expected to change hearing
co factor: Check B12 status first — masking B12 deficiency can itself worsen neurological function
titration: No titration; the single positive trial used 800 mcg daily in a population with low dietary folate and no fortification
starting dose: 400-800 mcg daily, ideally from food (leafy greens, legumes, fortified grains) with a supplement to fill the gap

Evidence

What the studies say

A three-year randomised trial in the Netherlands (Durga 2007, n=728) gave 800 mcg of folic acid daily to adults aged 50-70 with raised homocysteine and low folate status. Low-frequency hearing thresholds declined significantly less than placebo; high-frequency thresholds, which drive most functional difficulty, were unaffected. The setting matters: the Netherlands did not fortify flour with folic acid, so participants were relatively deplete. Observational data associate higher folate intake with lower presbycusis risk, but no replication trial has been run in a fortified population, and no trial has shown recovery of lost hearing.

Effects of folic acid supplementation on hearing in older adults: a randomized, controlled trial

Score: 9/10

2007

rct

n=728

Durga J, Verhoef P, Anteunis LJ +2 more

After 3 years, thresholds of the low frequencies increased by 1.0 dB in the folic acid group and by 1.7 dB in the placebo group (difference, -0.7 dB; P = 0.020). Folic acid supplementation did not affect the decline in hearing high frequencies.

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Safety

Caveats

Folic acid can mask B12 deficiency by correcting the anaemia while neurological damage continues — check B12 first. Benefit was limited to low frequencies, not the speech-critical range.

Less likely to help if

People in folate-fortified countries with adequate intake, and anyone with established sensorineural loss hoping for recovery.

Medical Disclaimer

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Individual results may vary. The statements on this website have not been evaluated by the Food and Drug Administration. Products and information are not intended to diagnose, treat, cure, or prevent any disease.