Background/Purpose:   Low Vitamin D levels are prevalent in Rheumatoid Arthritis (RA). We have previously reported that low vitamin D levels are associated with higher disease activity indicators and poorer patient reported outcomes (PROs). Our goal was to investigate the effect of vitamin D repletion and maintenance therapy in vitamin D deficient patients on clinical indicators of disease activity.

Methods: 139 persons who met 1987 ACR RA criteria were enrolled in an RCT at routine clinic visits from 1/2009 – 4/2011. Exclusion criteria included hypercalcemia and hyperparathyroidism. Tender and swollen joint counts (TJC, SJC) and evaluator disease assessments were performed. 25(OH)D levels were assessed using the Diasorin radioimmunoassay. Patients with 25(OH)D levels < 30 ng/ml were randomly assigned to receive either standard intensive therapy [50,000 IU ergocalciferol/week for 8 or 16 weeks] till repletion (25(OH)D > 30 ng/ml was achieved] + 16 weeks of maintenance therapy (50,000 IU ergocalciferol /month) or placebo for 16 weeks, followed by the above vitamin D protocol. At baseline visit, 83 of 139 (60%) patients had 25(OH)D levels < 30 ng/ml. Results show the effects of vitamin D repletion and maintenance therapy (independent of original treatment assignment).

Results: Patients had a mean (SD) age of 52.5 (12.8) yr, RA duration of 9.8 (9.6) yr and BMI of 31.8 (6.8) kg/m2 and were mostly female (83%), white (76%), well-educated (60% reported some college education) and non-smokers (61%). Of 73 who began repletion therapy, 58 were sufficient after 8 wks of therapy; 6 were sufficient after 16 weeks of therapy and 3 failed to achieve adequate levels. During maintenance, 62 people completed 8 wk and 61 completed 16 wk of therapy. Vitamin D increased an average of 71% (mean increase 17.3 [12.9]; range -22.4 – +57.8 ng/ml) during repletion then declined steady during maintenance (see Table). Increases in Vitamin D were inversely and moderately associated with baseline vitamin D (r=-.43; p<.001) but not with age, sex, minority status, BMI, RA duration or smoking status. Disease activity score (DAS) and TJC significantly (p<.05) increased during treatment and decreased during maintenance; other clinical indices were not significantly different at any time point.

Conclusion: Intensive repletion therapy modestly increased vitamin D levels in RA patients with 25(OH)D < 30 ng/ml. However, patients were unable to maintain adequate levels over 16 weeks of maintenance therapy. With the exception of tender joints which increased during treatment then returned to baseline levels following maintenance, other clinical indices remained stable throughout treatment. Thus, in RA patients who are insufficient, standardized intensive vitamin D protocols appear to only modestly increase circulating levels of 25(OH)D and do not impact clinical indicators of RA disease activity.