A 3-day regimen of folic acid supplementation may improve tear film parameters, with benefits including improved comfort, stability, volume, and overall quality of the ocular tear film.
Key Findings
Results
Folic acid supplementation significantly reduced dry eye symptom scores (SPEED questionnaire) after a 3-day regimen.
SPEED scores decreased from 7.0 (9.2) before supplementation to 4.0 (7.3) after supplementation
Difference was statistically significant (p < 0.001, Wilcoxon signed-rank test)
Measurements were taken before folic acid intake and 24 hours after the third dose
Results
Noninvasive tear breakup time (NITBUT) significantly increased after 3 days of folic acid supplementation, indicating improved tear film stability.
NITBUT increased from 5.5 (4.1) seconds before supplementation to 9.9 (6.7) seconds after supplementation
Difference was statistically significant (p < 0.001, Wilcoxon signed-rank test)
Higher NITBUT values indicate greater tear film stability
Results
Tear meniscus height (TMH) significantly increased after 3 days of folic acid supplementation, indicating improved tear volume.
TMH increased from 0.19 (0.05) mm before supplementation to 0.21 (0.03) mm after supplementation
Difference was statistically significant (p < 0.001, Wilcoxon signed-rank test)
Higher TMH values indicate greater tear volume
Results
Tear ferning (TF) scores significantly decreased after 3 days of folic acid supplementation, indicating improved tear film quality.
TF scores decreased from 1.3 (0.6) before supplementation to 0.9 (0.9) after supplementation
Difference was statistically significant (p < 0.001, Wilcoxon signed-rank test)
Lower TF scores indicate better overall tear film quality
Methods
The study recruited 46 young healthy participants with no pre-existing eye diseases and used a single-arm pre-post intervention design without a control group.
Participants included 24 males and 22 females aged 19 to 34 years (mean age 23.2 ± 3.4 years)
All participants received oral folic acid tablets at a daily dose of 1 mg for three consecutive days
No control group participated in the study
Tests administered included the SPEED questionnaire, NITBUT, TMH, and tear ferning tests
Authors described the study as a pilot study and noted results are 'preliminary and hypothesis generating'
Almutairi M, Almutleb E, Alqahtani M, El-Hiti G, Altoaimi B, Alghamdi M, et al.. (2025). Exploring the potential of short-term oral folic acid on the ocular tear film: An intervention study.. Science progress. https://doi.org/10.1177/00368504251410785