ARVO 2023: No evidence linking dietary vitamin intake and attenuation of dry eye disease

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Dietary vitamin intake is not associated with attenuated dry eye disease (DED), according to a recent study reported at the Association of Research in Vision and Ophthalmology annual meeting.

Interestingly, first author Long Nguyen, MD, MS, from the Department of Plastic and Reconstructive Surgery, Oslo Universitetssykehus, Norway reported instead that vitamins C and E may actually be associated with a slightly increased risk of DED.

The rationale for the study was that adequate vitamin intake is considered essential for ocular health and is thought to also play a role in DED.

The investigators conducted a large population-based, cross-sectional study to attempt to clarify the association between dietary vitamin intake and the risk of DED.

The 51,551 study participants (mean age, 51.2 years; 60% women) were from the population-based Lifelines cohort. DED was assessed via the Women’s Health Study dry eye questionnaire, which defines DED 2 ways: either based on a previous DED diagnosis established by a clinician or based on highly symptomatic dry eye (“often” or “constant” symptoms of both dryness and irritation of the eyes), the authors described.

The authors assessed the total daily intake of vitamins A, B2, B6, B12, C, and E from food and drinks (excluding supplements) using the Food Frequency Questionnaires.

The analysis of the relationship between DED and vitamin intake with adjustment for demographics, body mass index, smoking status, vitamin supplement use, and 48 comorbidities.

They also investigated an association between DED and meeting the recommended daily intake of vitamins, based on the NIH recommendations. In addition, the authors repeated the analyses separately in participants who did not use vitamin supplements to remove the possible impact associated with supplement use.

Results of the DED analysis

DED based on the definition used in the Women’s Health Study was present in 9.1% of the population.

The authors reported, “Higher intakes of vitamin C and vitamin E increased the odds for having DED.” In addition, the participants who satisfied the recommended intake of vitamins C and E, had increased odds of developed DED, ie, 14% and 10%, respectively, compared with participants who did not satisfy the recommended intake of those vitamins.

The intake levels of vitamins A, B2, B6, and B12 were not significantly associated with a risk of developing DED. In subjects who did not use vitamin supplements, the associations were similar to those seen in the total population.

The investigators concluded, “This large population-based study found no evidence that dietary vitamin intakes attenuated the risk of DED. Instead, vitamin C and, to a lesser extent, vitamin E, may be associated with a slightly increased risk of DED. The causes for the direction of this association should be explored further as it went against our hypothesis and previous findings.”