Proceedings of the Nutrition Society

The annual Irish Section Postgraduate meeting hosted by the University of Ulster, White Horse Hotel, Derry/Londonderry.16–18 February 2011,

Irish Section Postgraduate Symposium

An evaluation of vitamin D status in individuals with systemic lupus erythematosus

Leanne C. Breslina1, Pamela J. Mageea1, Julie M. W. Wallacea1 and Emeir M. McSorleya1 c1

a1 Northern Ireland Centre for Food and Health (NICHE), School of Biomedical Sciences, University of Ulster, Cromore Road, Coleraine BT52 1SA, UK

Abstract

Systemic lupus erythematosus (SLE) is a multi-system inflammatory disease where genetic susceptibility coupled with largely undefined environmental factors is reported to underlie the aetiology of the disease. One such factor is low vitamin D status. The primary source of vitamin D is endogenous synthesis following exposure of the skin to UVB light. Photosensitivity, sunlight avoidance and the use of sun protection factor in combination with medications prescribed to treat the symptoms of the disease, puts SLE patients at increased risk of vitamin D deficiency. Decreased conversion of 25-hydroxyvitamin D to the metabolically active form, 1,25-dihydroxyvitamin D3, is possible, due to renal impairment common in SLE putting additional stress on vitamin D metabolism. The majority of studies have identified low 25-hydroxyvitamin D in SLE patients, albeit using varying cut-offs (<25 to <80 nmol/l). Of these studies, fifteen have investigated a link between status and disease activity with conflicting results. Variation with disease activity index measures used alongside methodological limitations within the study design may partially explain these findings. This review discusses the importance of optimal vitamin D status in SLE, critically evaluates research carried out to date that has investigated vitamin D in SLE, and highlights the need for a well-designed observational study that controls for diet, medication use, dietary supplements, UV exposure and seasonality, that uses sensitive methods for measuring vitamin D status and disease activity in SLE to conclusively establish the role of vitamin D in SLE.

(Online publication August 24 2011)

Correspondence

c1 Corresponding author: Dr Emeir McSorley, fax +44 2870 123023, email em.mcsorley@ulster.ac.uk