METHODS: THE FOLLOWING DATABASES WERE SEARCHED: MEDLINE, Scopus, Web of Knowledge and CINAHL, using the terms "lupus", "systemic lupus erythematosus", "SLE and "vitamin D". We included only adult human studies published in the English language between 2000 and 2012.The reference lists of included studies were thoroughly reviewed in search for other relevant studies.
RESULTS: A total of 22 studies met the selection criteria. The majority of the studies were observational (95.5%) and cross sectional (90.9%). Out of the 15 studies which looked into the association between vitamin D and SLE disease activity, 10 studies (including the 3 largest studies in this series) revealed a statistically significant inverse relationship. For disease damage, on the other hand, 5 out of 6 studies failed to demonstrate any association with vitamin D levels. Cardiovascular risk factors such as insulin resistance, hypertension and hypercholesterolaemia were related to vitamin D deficiency, according to 3 of the studies.
CONCLUSION: There is convincing evidence to support the association between vitamin D levels and SLE disease activity. There is paucity of data in other clinical aspects to make firm conclusions.