Background Over the last decade Vitamin D (Vit D) has been the focus of considerable interest as a potential immunomodulator in a variety of conditions including autoimmune disease. Its influence in juvenile idiopathic arthritis (JIA) however is unclear. We therefore wished to clarify a possible link with the currently available evidence.

Objectives To establish a link between Vit D insufficieny and JIA

Methods A systematic literature review was undertaken using Embase, Cochrane and Medline for manuscripts up to May 2011. Search results were then assessed by 2 independent reviewers and relevant articles were further screened by full text review. Only those specifically reporting Vit D levels or its supplementation in JIA (ages between 0-18 years) were selected. Meta-analysis was performed where possible with those papers reporting similar data and analysis techniques.

Results In total, 19 papers (n=745) were included in the review. Fourteen papers quoted 25(OH)D levels within their study groups with a mean of 24.56 ng/ml (range: 11.5-56.4 ng/ml) in a total of 529 children. Eleven papers quoted 1,25(OH)₂D levels with a mean of 31.09 pg/ml (range 6.1-65.0 pg/mol) in a total of 518 children. Three studies reporting the prevalence ofVit D deficiency in their cohorts found that up to 82% of children had insufficient levels. Five papers reported Vit D levels by JIA subtype and showed lower levels of both 25(OH)D [mean 15.35, range 8.5 -24.5 ng/ml] and 1,25(OH)₂D [ mean 22.89, range 5.6-50 pg/ml] in systemic JIA. Four papers reported Vit D supplementation in JIA however the treatment effect was unclear.

Conclusions At present no clear evidence exists to support a link between Vit D level and JIA. Furthermore the role of Vit D supplementation in the management of JIA is lacking. Despite Vit D levels appearing to be lower in JIA, interpretation is problematic as no agreed definition of Vit D deficiency exists in this population. A need remains therefore to standardise Vit D levels in the paediatric population and in JIA.

Disclosure of Interest None Declared