Background The benefit of vitamin D on SLE global and renal activity have now been proven by both cohort studies and a clinical trial. The benefits on cardiovascular risk factors, however, are less well understood.

Objectives We present the first longitudinal study on hyperlipidemia.

Methods A within-person aanalysis addressed the question of whether a person tends to have higher cholesterol when her vitamin D is lower than her average vitamin D. To assess this, for each visit, we calculated the difference between the vitamin D level at that visit and the person's average of vitamin D. Differences in the range of vitamin D <50 ng/mL were distinguished from differences in the range above 50 ng/mL. Then we modelled the relationship between these differences in vitamin D and the difference between the person's cholesterol at each visit and the person's average cholesterol.

ResultsThis means that at a particular clinic visit, if a person's vitamin D is higher than the person's mean vitamin D by 10 ng/mL and the person has vitamin D below 40 ng/mL, then the expected cholesterol will decrease by 3.4 mg/dL. There is no significant effect of higher vitamin D among those whose mean vitamin D exceeds 50.

Conclusions Vitamin D supplementation (in those whose level is below 40 ng/mL) has a significant benefit on total cholesterol that is independent of age, sex, ethnicity, Plaquenil, prednisone and body mass index. Vitamin D supplementation - as it also helps systolic blood pressure - is both important for SLE activity and for reduction of cardiovascular disease.

Disclosure of Interest None declared