Low vitamin D levels and genetic polymorphisms may play a role in uveitis

This systematic review of the literature focuses on links between vitamin D deficiency, genetic polymorphisms of vitamin D, and uveitis.

Study design

A literature search was conducted to find relevant articles concerning vitamin D and uveitis published up to March 2021. Sixteen studies were included in this review, with either retrospective case-control or observational case-control study designs. The studies enrolled adults with noninfectious anterior, intermediate, or posterior uveitis, or panuveitis, with documented serum vitamin D (calcidiol) levels. HLA-B27-associated acute anterior uveitis, Vogt-Koyanagi-Harada (VKH) disease, Behçet disease, sarcoidosis-associated uveitis, and juvenile idiopathic arthritis-associated uveitis were described in the studies. Systemic diseases or medications known to reduce vitamin D levels were cause for exclusion.

Outcomes

Hypovitaminosis D and lower vitamin D levels are associated with uveitis activity and the risk of noninfectious uveitis and scleritis. A high calcitriol/calcidiol ratio is suggestive of ocular sarcoidosis, due to the hypercalcemia and increased production of calcitriol seen in patients with this condition. There is also evidence of the effect of gene polymorphisms of the vitamin D family, including CYP2R1, CYP27B1, CYP24A1, and DHCR7, on uveitis development.

Limitations

The observational design of most of studies included in this review can interfere with causality of conclusions.

Clinical significance

Detailed investigation of the pathophysiologic mechanisms of genetic polymorphisms related to uveitis may lead to improved diagnostics and revision of the current standard of care of patients with uveitis.