Endocrine Abstracts

Vitamin D deficiency has been implicated in the pathogenesis of autoimmune diseases, such as diabetes mellitus type 1 and multiple sclerosis. Reduced vitamin D intake has been linked to increased susceptibility to the development of rheumatoid arthritis (RA) and vitamin D deficiency has been found to be associated with disease activity in RA patients. The aim was to evaluate vitamin D status in RA patients and to assess the relationship between vitamin D levels and disease activity.

In a cohort of 44 patients suffering from RA 25(OH)D3 levels, parathyroid hormone levels, C-reactive protein and ESR were measured. Disease activity was evaluated by calculating the DAS28 score. A control group (n=44), matched for age and sex, was evaluated as well. All patients fulfilled the American College of Rheumatology criteria for the classification of RA.

In the cohort of 44 RA patients 25(OH)D3 levels were found to be low as compared to the control group, 25(OH)D3 being 15.36±1.09 and 24.9±1.2 ng/ml, in the patient and control group respectively (Student’s t-test, P<0.05). Parathyroid hormone levels were 70.82±7.22 pg/ml (normal values 10.0–65.0 pg/ml), CRP 7.59±1.64 mg/l (normal values <3 mg/l) and ESR was 36.7±4.5 mm/h in the group of RA patients. Levels of 25(OH)D3 were found to be negatively correlated to the DAS28 score, correlation coefficient being −0.065. Levels of 25(OH)D3 were also found to be negatively correlated to CRP and ESR, correlation coefficient being −0.11 and −0.16 respectively.

It appears that vitamin D deficiency is highly prevalent in RA patients, and that vitamin D deficiency may be linked to disease severity in RA. As vitamin D deficiency has been linked to diffuse musculoskeletal pain, these results have therapeutic implications. Vitamin D supplementation may be needed both for the prevention of osteoporosis as well as for pain relief in rheumatoid arthritis patients.

Declaration of interest: The authors declare that there is no conflict of interest that could be perceived as prejudicing the impartiality of the research project.

Funding: This research did not receive any specific grant from any funding agency in the public, commercial or not-for-profit sector.