Effect of a Mediterranean dietary pattern and vitamin D levels on Dry Eye syndrome

The aim of this study was to evaluate the association between a Mediterranean dietary pattern (MeDi) and Vitamin D levels on dry eye syndrome (DES).

This was a cross-sectional study. Male patients seen in the Miami Veterans Affairs eye clinic with normal eyelid, corneal, and conjunctival anatomy were recruited to participate in the study. The patients filled out the 2005 Block Food Frequency Questionnaire and the Dry Eye Questionnaire 5 and underwent measurement of tear film parameters. The serum level of 25-hydroxy vitamin D was also measured. The main outcome measures included the association among MeDi, Vitamin D levels, and DES.

Two hundred forty-seven men underwent DES testing. The mean patient age was 69 years (range, 55-95). Using latent class analysis to categorize the presence or absence of disease and quantify its severity, we found that adherence to the MeDi was positively associated with the risk of having DES (odd ratio 1.25, 95% confidence interval, 1.06-1.47, P = 0.007) and with increasing disease severity. Vitamin D levels were not significantly associated with the presence or severity of disease. However, higher levels of vitamin D were associated with decreased DES symptoms, with a -1.24 decrease in median Dry Eye Questionnaire 5 score for every 10-U increase in Vitamin D levels (P = 0.01).

Adherence to the MeDi was not associated with a beneficial effect on DES. Higher vitamin D levels had a small but favorable effect on DES symptoms.