Vitamin D supplementation linked to decreased uveitis activity

The authors examined patterns of serum vitamin D levels among people with active and inactive noninfectious uveitis.

Study design

This prospective case-control study included 151 adults with active and inactive noninfectious uveitis recruited from 2 Victorian tertiary hospitals and 1 private ophthalmic practice. All participants had their serum 25-hydroxy vitamin D measured and completed a questionnaire on vitamin D intake and ultraviolet light exposure. Serum 25-hydroxy vitamin D levels were compared between active and inactive uveitis groups and with local population estimates.

Outcomes

Participants with active uveitis had significantly lower serum 25-hydroxy vitamin D levels than inactive uveitis patients and local population-based estimates. The median level of serum vitamin D in the 74 patients with active uveitis was 46 nmol/l, significantly lower than the 77 patients with inactive disease at 64 nmol/l (P<0.001). In addition, the active uveitis group had lower median serum vitamin D levels than the local population median of 62 nmol/l.

Vitamin D supplementation was found to be associated with decreased uveitis activity, as was sun exposure in those with vitamin D deficiency. These results suggest that vitamin D supplementation should be studied as an option for the prevention of uveitis relapse in at-risk patients.

Limitations

It is not possible to know whether the low vitamin D level is truly contributing to uveitis activity. Questionnaires are also prone to bias as they rely on patients to self-report "time in sunlight." A prospective randomized trial design would be needed to eliminate other confounders.

Clinical significance

These findings suggest vitamin D supplementation is a relatively inexpensive and benign addition to a treatment protocol for uveitis patients.