Abstract
Background and aims Studies have shown an association between levels of Vitamin D and incidence and activity of autoimmune diseases. The purpose of this study was to examine correlation between vitamin D levels in RA and SLE patients compared to controls without autoimmune disease. Our hypothesis was that low vitamin D is ubiquitous in the general population and not related to specific autoimmune disease.
Methods This was a retrospective, single centre, hospital-affiliated outpatient cohort study. A systematic review of the electronic medical record generated a patient list with the diagnosis codes for RA, SLE, osteoarthritis (OA) and Fibromyalgia. Vitamin D levels were characterised as follows: deficiency (<20 ng/mL), insufficiency (20–30 ng/mL) and normal (>30 ng/ml). A total of 115 patents were included, and, SAS9.3 statistical tool was used to analyse the data.
Results A total of 23 patients had RA, 27 had SLE and 65 had non-inflammatory disease (OA and fibromyalgia). There was no statistically significant difference in the vitamin D levels in RA, SLE versus the non-inflammatory group.
We did note of interest that in the RA group, a body mass index (BMI) above 35 had lower Vitamin D levels, as opposed to the lupus and control group groups.
Conclusions In our study, we found no relationship between the levels of vitamin D levels and the presence or absence of autoimmune disease. We did find a relationship between the BMI and Vitamin D levels, and this will need further study.