Vitamin D levels and exposures in active and inactive uveitis patients

Abstract

Purpose : While there are known links between autoimmunity and vitamin D deficiency, limited research about a clinical relationship between serum vitamin D levels and uveitis activity exists. We performed an observational case-control study comparing vitamin D levels and patterns of exposure between patients with active and inactive non-infectious uveitis.

Methods : 75 patients with active non-infectious uveitis and 77 patients with inactive non-infectious uveitis were recruited from two Victorian tertiary hospitals and a private ophthalmic practice. Population-standard serum vitamin D levels were obtained from the Australian Bureau of Statistics (ABS) Nutrition Survey 2011-2012. All patients had a serum 25-hydroxyvitamin-D measurement, and completed a questionnaire on vitamin D intake and UV exposure. The Mann-Whitney test was used to compare vitamin D levels between active groups and inactive controls, as well as population data. The Kendall’s tau test was used to compare the results of the questionnaire between active and inactive groups.

Results : The median (IQR) level of serum vitamin D in active uveitis was 47nmol/L (29,70), significantly lower than the inactive control group at 64nmol/L (52,79) (p<0.001). The active uveitis group also had lower serum vitamin D levels than ABS controls, who had a median (IQR) of 62nmol/L (46,77). In our questionnaire analysis, vitamin D supplementation was demonstrated to be significantly related to decreased uveitis activity (tau-a=0.1956, p=0.022). In a sub-analysis of vitamin D deficient participants, sun exposure was significantly related to decreased uveitis activity (tau-a=0.1851, p=0.0153 and tau-a=0.1780, p=0.0200 for weekday and weekend analyses respectively).

Conclusions : Participants with active uveitis had significantly lower serum vitamin D levels than inactive uveitis patients and population-standard controls. Furthermore, vitamin D supplementation and sun exposure were found to be associated with decreased uveitis activity, suggesting the potential for vitamin D supplementation as an option for preventative management. Further studies are recommended to determine the efficacy of vitamin D supplementation in decreasing relapses of uveitis.

This is an abstract that was submitted for the 2018 ARVO Annual Meeting, held in Honolulu, Hawaii, April 29 - May 3, 2018.