1,25 dihydroxy vitamin D3 has immunomodulatory functions in rheumatoid arthritis (RA) and is an anti-osteoporotic agent. No studies exist to assess its pain-relieving action in RA.
An open-labeled randomized trial comparing triple disease-modifying anti-rheumatic drug (DMARD) therapy and 500 IU 1,25 dihydroxy vitamin D3 + calcium combination versus triple DMARD and calcium alone was conducted. The primary outcome was the time to pain relief by patients' visual analogue scale (VAS). Changes in VAS after first achievement of pain relief and after 3 months were noted. 25 hydroxy-vitamin D levels were correlated with disease activity scor (DAS-28), adjusting for sun exposure. Comparisons between the groups were done by Mann-Whitney test and independent samples test.
Patients on the vitamin D group (n = 59) had higher pain relief than the control group (n = 62) (50%vs. 30%, P = 0.006). There was no significant difference in the time taken for initial pain relief between the two groups. Occurrence of hypovitaminosis D in RA patients (68.1%) is comparable to published normal Indian prevalence. There was no correlation between 25 hydroxy vitamin D levels and disease activity.
Supplementation of 500 IU of 1,25 dihydroxy vitamin D3 daily to previously DMARD-naïve patients with early RA along with triple DMARD therapy results in a significantly higher pain relief at the end of 3 months. The number needed to treat for this additional pain relief was 5. The prevalence of vitamin D deficiency in the study population was 68.1%.