A randomised, double-blind, placebo-controlled study assessing the efficacy of high doses of vitamin D on functional disability in patients with rheumatoid arthritis.

OBJECTIVES

To evaluate the short-term efficacy of vitamin D (cholecalciferol) supplementation on functional disability in RA patients.

METHODS

1. Patients: RA (ACR 1987 revised criteria) in non-remission (DAS28 >2.6) whose treatment was not expected to be changed over a 3-month period following inclusion and presenting with vitD deficits (serum 25OHD <30ng/mL). 2) Study design: prospective randomised placebo-controlled trial (NCT02243800). 3) Study arms: either vitD ampoules (cholecalciferol 100,000IU) or placebo. 4) Outcome measures: primary: improvement in patients' functional disability using the Health Assessment questionnaire (HAQ); secondary: improvement in DAS28ESR, DAS28CRP, ESR, CRP, RAID score, fatigue (EVA and FACIT), and SF36.

RESULTS

Overall, 59 patients were included, 83.1% females, aged 59.8±10.9 years on average, with RA for 17.0±9.7 years. Thirty patients received placebo and 29 vitD. At 6 months, HAQ scores tended to be increased in the placebo group (+0.08±0.25), while slightly numerically decreased in the vitD group (-0.03±0.23) (p=0.11). After adjusting for age, gender, season, and initial vitD status, the between-group difference achieved statistically significance (p=0.046). After adjusting for age, gender, season, and initial vitD status, there was no significant difference in the secondary criteria between the 2 groups except for ESR and CRP (p=0.002 and 0.04, respectively).

CONCLUSIONS

In this randomised, double-blind, placebo-controlled clinical trial in patients with RA and VitD deficiency, high doses of cholecalciferol resulted in a statistically significant improvement in functional disability at month 6, which, however, was clinically not relevant.