Effect of Vitamin D Supplementation in Rheumatoid Arthritis

Rheumatoid arthritis (RA) is an autoimmune disorder characterised by chronic inflammation in the synovial membrane, joints, and, occasionally, extra-articular organs. It carries risk of disability and early death. Studies assessing association between 25-OH Vitamin D (Vit D) levels and RA have produced conflicting results. No consensus exists on susceptibility to RA and the effect of supplementation on disease activity. Vit D deficiency is common in India, with estimated prevalence ranging from 37% to 99%.

A total of 90 participants with active RA on stable treatment received Vit D and calcium supplementation for 90 days. Clinical disease activity, disability, quality of life and pain indices were assessed at baseline and after 90 days.

There was a statistically significant reduction in Clinical Disease Activity Index (CDAI) (6.68 ± 3.2 to 5.65 ± 4.3), associated with an increase in World Health Organization Quality of Life - Brief questionnaire (WHO-QOL BREF) (59.7 ± 10.75 to 61.5 ± 11.1). There was a statistically significant decrease in Indian Health Assessment Questionnaire-Disability Index (HAQ-DI) (0.61 ± 0.63 to 0.56 ± 0.64) and pain visual analogue scores (VAS) (4.5 ± 0.94 to 4.37 ± 0.84) by day 90. The prevalence of Vit D deficiency was 47.8%.

Vit D and calcium supplementation was associated with favourable changes in disease activity, pain, and quality of life. It may be considered as an adjunct for management of RA, pending confirmation in controlled trials. The study was prospectively registered in the Clinical Trials Registry of India (CTRI/2021/04/033032).