Study Links Vitamin D Deficiency to Higher Risk of Dry Eye Disease

Key Takeaways

• A large retrospective cohort study found that adults with vitamin D deficiency had a significantly higher risk of developing dry eye disease 

• Researchers analyzing millions of patient records reported a 28.6% increased risk of dry eye disease among individuals with vitamin D deficiency

• The findings suggest vitamin D may play a role in ocular surface health and highlight the potential importance of screening for deficiency in patients with dry eye symptoms

A large new study published in the American Journal of Ophthalmology suggests that adults with vitamin D deficiency may face a significantly increased risk of developing dry eye disease (DED), highlighting a potential modifiable factor in one of the most common ocular surface conditions.¹

Researchers conducted a retrospective cohort study using electronic health records from the TriNetX U.S. Collaborative Network, examining millions of adults over nearly two decades. After propensity score matching to balance demographics and health factors, the final analysis included more than 6 million adults with vitamin D deficiency and an equal number of matched controls without the deficiency.

The study tracked the incidence of newly diagnosed dry eye disease using ICD-10 diagnostic codes and evaluated long-term risk patterns between the two groups.

During follow-up, 3.3% of individuals with vitamin D deficiency developed dry eye disease, compared with 2.7% of those without the deficiency. Statistical analysis showed that vitamin D deficiency was associated with a 28.6% higher risk of developing dry eye disease (hazard ratio 1.286).

Researchers also found that the cumulative incidence of dry eye disease increased over time in the vitamin D–deficient cohort. For example, after 5 years, the incidence reached 3.58% in the deficient group compared with 2.89% in controls, with the gap widening further over longer follow-up periods.

The findings align with biological evidence suggesting that vitamin D plays a role in regulating inflammation and immune responses on the ocular surface. Vitamin D receptors are present in eye tissues, and experimental research indicates that active vitamin D may reduce corneal epithelial inflammation and oxidative stress.

Based on the results, the researchers suggest that screening for vitamin D deficiency could be clinically relevant in patients with dry eye symptoms. Correcting low vitamin D levels may complement standard treatments, though supplementation should follow general medical guidelines rather than be used as a standalone therapy for DED.

The authors noted several limitations, including reliance on diagnostic codes rather than laboratory measurements of vitamin D levels or standardized dry eye tests. Additionally, the retrospective design means the study cannot establish a causal relationship between vitamin D deficiency and dry eye disease.

Future prospective studies and randomized trials will be needed to determine whether vitamin D supplementation can reduce the risk or severity of dry eye disease and to better understand the underlying mechanisms linking nutrition and ocular surface health.

Reference

1. Shmushkevich SB, Bajrami S, Beauchamp B, et al. Vitamin D deficiency and dry eye disease: a retrospective cohort study. Am J Ophthalmol. Published online February 26, 2026. doi:10.1016/j.ajo.2026.02.036.

Originally published online on Eyewire.