Background Some studies suggest that the risk for and severity of systemic lupus erythematosus (SLE) can be modified by certain nutrients. The aim of this study was to investigate the association between diet and glucocorticoid (GC) treatment, as a proxy for disease activity, in patients with SLE.

Methods We included 111 patients with SLE from the SLE Vascular Impact Cohort (SLEVIC). Dietary data were linked with data on GC treatment during a 2-year period. The association between diet and GC treatment was analysed with logistic regression. GC treatment and unchanged/increased doses were considered a proxy for active SLE.

Results During the 2-year period, 54 patients (48.6%) had continued GC treatment. Dietary vitamin D was associated with GC treatment (OR=2.70–2.85 (95% CI 1.00 to 8.11)), whereas alcohol was inversely associated with GC treatment (OR=0.28–0.39 (95% CI 0.10 to 98)). Beta-carotene, fatty acid C18:2 and vitamin B₆ were inversely associated with unchanged/increased GC dose (OR=0.29–0.30 (95% CI 0.10 to 0.90)). Finally, total energy intake was associated with GC doses >5.0 mg/day and >7.5 mg/day, explaining a direct association between 35 nutrients and higher GC dose levels (OR=2.98–23.82 (95% CI 1.01 to 203.88)).

Discussion Dietary vitamin D did not protect against lupus activity. Beta-carotene, fatty acid C18:2 and vitamin B₆ may protect against increased GC dose. The inverse association between alcohol intake and GC treatment/lupus activity may provide a partial explanation for the link between moderate alcohol intake and reduced risk of SLE. The association between higher dietary intake and higher GC dose levels indicated GC's influence on increasing appetite.