Background Anaemia of inflammation (AI) and vitamin D deficiency can both contribute to significant morbidity in rheumatoid arthritis (RA) patients. The potential relationship between them remains poorly understood. A common feature of RA associated with AI is immune activation and production of inflammatory cytokines. In AI, proinflammatory cytokines affect iron metabolism. Vitamin D is recognized as having potent immunomodulatory properties that has prompted its potential use in autoimmune diseases including RA.
Objectives To determine the prevalence of 25 hydroxyvitamin D deficiency in RA patients with AI and to assess the association between 25 hydroxyvitamin D and AI and the efficacy of vitamin D supplementation.
Methods Eighty-five patients all fulfilling the ACR criteria for RA were enrolled in this 16-week randomized placebo-controlled study. Inclusion criteria included premenopausal women and men of the same body mass index and ethnicity having AI, that is, low circulating iron <60μ/dl and no evidence of iron deficiency anaemia Tfr/log ferritin <15. Vitamin D deficiency was defined as serum levels <30ng/ml. Fifty-five healthy age-sex-BMI and ethnically matched controls were also recruited. Patients were randomized in a 1:1 ratio to receive either oral cholecalciferol 2000IU/day or placebo for 4 months together with standard RA treatment. Outcome measures included improvement of AI, inflammatory markers before and after vitamin D supplementation. Vitamin D levels were measured by Liaison immunoassay (normal 30-100ng/ml). Serum levels of proinflammatory cytokines IL-6 and TNF-alpha and acute phase reactants: hsCRP, ESR and fibrinogen and blood indices were measured at baseline and after vitamin D supplementation.
Results The prevalence of vitamin D deficiency was 54% in RA patients with AI compared to 12% in the healthy controls, p=0.006. There was a significant positive correlation between vitamin D deficiency and AI, r =0.537; p=0.003. Following vitamin D supplementation a statistically significant improvement in the indices of AI occurred. Inflammatory markers and proinflammatory cytokines decreased significantly after vitamin D supplementation.
Conclusions Vitamin D may attenuate inflammation and further studies to confirm whether vitamin D supplementation improves AI are needed.
Disclosure of Interest None Declared
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